refactor(spdx-utils): Move operator-relared code to a separate file

Improve overview a bit my splitting the large `Extensions.kt` and
grouping operator code.

Signed-off-by: Sebastian Schuberth <sebastian@doubleopen.org>

utils/spdx/src/main/kotlin/Extensions.kt

@@ -17,8 +17,6 @@
  * License-Filename: LICENSE
  */
 
-@file:Suppress("TooManyFunctions")
-
 package org.ossreviewtoolkit.utils.spdx
 
 import java.lang.invoke.MethodHandles
@@ -30,32 +28,6 @@ import org.ossreviewtoolkit.utils.spdx.SpdxExpression.Strictness
 
 private val logger = loggerOf(MethodHandles.lookup().lookupClass())
 
-/**
- * Create an [SpdxExpression] by concatenating [this][SpdxLicense] and [other] using [SpdxOperator.AND].
- */
-infix fun SpdxLicense.and(other: SpdxLicense) = this and other.toExpression()
-
-/**
- * Create an [SpdxExpression] by concatenating [this][SpdxLicense] and [other] using [SpdxOperator.AND].
- */
-infix fun SpdxLicense.and(other: SpdxExpression) = SpdxCompoundExpression(toExpression(), SpdxOperator.AND, other)
-
-/**
- * Create an [SpdxExpression] by concatenating [this][SpdxLicense] and [other] using [SpdxOperator.OR].
- */
-infix fun SpdxLicense.or(other: SpdxLicense) = this or other.toExpression()
-
-/**
- * Create an [SpdxExpression] by concatenating [this][SpdxLicense] and [other] using [SpdxOperator.OR].
- */
-infix fun SpdxLicense.or(other: SpdxExpression) = SpdxCompoundExpression(toExpression(), SpdxOperator.OR, other)
-
-/**
- * Create an [SpdxExpression] by concatenating [this][SpdxLicense] and [exception] using [SpdxExpression.WITH].
- */
-infix fun SpdxLicense.with(exception: SpdxLicenseException) =
-    SpdxLicenseWithExceptionExpression(toExpression(), exception.id)
-
 /**
  * Create an [SpdxLicenseIdExpression] from this [SpdxLicense].
  */

utils/spdx/src/main/kotlin/SpdxExpression.kt

@@ -601,28 +601,3 @@ data class SpdxLicenseReferenceExpression(
 
     override fun getLicenseUrl(): String? = null
 }
-
-/**
- * An SPDX operator for composite expressions as defined by version 2.2 of the [SPDX specification, annex D.4][1].
- *
- * [1]: https://spdx.github.io/spdx-spec/v2.2.2/SPDX-license-expressions/#d4-composite-license-expressions
- */
-enum class SpdxOperator(
-    /**
-     * The priority of the operator. An operator with a larger priority value binds stronger than an operator with a
-     * lower priority value. Operators with the same priority bind left-associative.
-     */
-    val priority: Int
-) {
-    /**
-     * The conjunctive binary "AND" operator to construct a new license expression if required to simultaneously comply
-     * with two or more licenses, where both the left and right operands are valid [SpdxExpressions][SpdxExpression].
-     */
-    AND(1),
-
-    /**
-     * The disjunctive binary "OR" operator to construct a new license expression if presented with a choice between
-     * two or more licenses, where both the left and right operands are valid [SpdxExpressions][SpdxExpression].
-     */
-    OR(0)
-}

utils/spdx/src/main/kotlin/SpdxOperator.kt

@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2017 The ORT Project Authors (see <https://github.com/oss-review-toolkit/ort/blob/main/NOTICE>)
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ * License-Filename: LICENSE
+ */
+
+package org.ossreviewtoolkit.utils.spdx
+
+/**
+ * An SPDX operator for composite expressions as defined by version 2.2 of the [SPDX specification, annex D.4][1].
+ *
+ * [1]: https://spdx.github.io/spdx-spec/v2.2.2/SPDX-license-expressions/#d4-composite-license-expressions
+ */
+enum class SpdxOperator(
+    /**
+     * The priority of the operator. An operator with a larger priority value binds stronger than an operator with a
+     * lower priority value. Operators with the same priority bind left-associative.
+     */
+    val priority: Int
+) {
+    /**
+     * The conjunctive binary "AND" operator to construct a new license expression if required to simultaneously comply
+     * with two or more licenses, where both the left and right operands are valid [SpdxExpressions][SpdxExpression].
+     */
+    AND(1),
+
+    /**
+     * The disjunctive binary "OR" operator to construct a new license expression if presented with a choice between
+     * two or more licenses, where both the left and right operands are valid [SpdxExpressions][SpdxExpression].
+     */
+    OR(0)
+}
+
+/**
+ * Create an [SpdxExpression] by concatenating [this][SpdxLicense] and [other] using [SpdxOperator.AND].
+ */
+infix fun SpdxLicense.and(other: SpdxLicense) = this and other.toExpression()
+
+/**
+ * Create an [SpdxExpression] by concatenating [this][SpdxLicense] and [other] using [SpdxOperator.AND].
+ */
+infix fun SpdxLicense.and(other: SpdxExpression) = SpdxCompoundExpression(toExpression(), SpdxOperator.AND, other)
+
+/**
+ * Create an [SpdxExpression] by concatenating [this][SpdxLicense] and [other] using [SpdxOperator.OR].
+ */
+infix fun SpdxLicense.or(other: SpdxLicense) = this or other.toExpression()
+
+/**
+ * Create an [SpdxExpression] by concatenating [this][SpdxLicense] and [other] using [SpdxOperator.OR].
+ */
+infix fun SpdxLicense.or(other: SpdxExpression) = SpdxCompoundExpression(toExpression(), SpdxOperator.OR, other)
+
+/**
+ * Create an [SpdxExpression] by concatenating [this][SpdxLicense] and [exception] using [SpdxExpression.WITH].
+ */
+infix fun SpdxLicense.with(exception: SpdxLicenseException) =
+    SpdxLicenseWithExceptionExpression(toExpression(), exception.id)