Add a way to get all unique and virtual accounts from the economy se…

…rvice (#2152)

* Add a way to get all unique and virtual accounts from the economy service

* Add collection getters

* Use the same phrasing as the catalog registry

* Fix method names

* Remove unused import

src/main/java/org/spongepowered/api/service/economy/EconomyService.java

@@ -31,9 +31,11 @@
 import org.spongepowered.api.service.economy.account.UniqueAccount;
 import org.spongepowered.api.service.economy.account.VirtualAccount;
 
+import java.util.Collection;
 import java.util.Optional;
 import java.util.Set;
 import java.util.UUID;
+import java.util.stream.Stream;
 
 /**
  * Represents a service for managing a server economy.
@@ -108,6 +110,34 @@ public interface EconomyService extends ContextualService<Account> {
      */
     Optional<Account> getOrCreateAccount(String identifier);
 
+    /**
+     * Gets a {@link Stream} of all available {@link UniqueAccount}s.
+     *
+     * @return A stream of all {@link UniqueAccount}s.
+     */
+    Stream<UniqueAccount> streamUniqueAccounts();
+
+    /**
+     * Gets a {@link Collection} of all available {@link UniqueAccount}s.
+     *
+     * @return A Collection of all {@link UniqueAccount}s.
+     */
+    Collection<UniqueAccount> getUniqueAccounts();
+
+    /**
+     * Gets a {@link Stream} of all available {@link VirtualAccount}s.
+     *
+     * @return A stream of all {@link VirtualAccount}s.
+     */
+    Stream<VirtualAccount> streamVirtualAccounts();
+
+    /**
+     * Gets a {@link Collection} of all available {@link VirtualAccount}s.
+     *
+     * @return A Collection of all {@link VirtualAccount}s.
+     */
+    Collection<VirtualAccount> getVirtualAccounts();
+
     /**
      * Deletes the account for the user with the specified {@link UUID}.
      *