fix: Missing window icon under wayland (#1633)

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### Problem description
When running ImHex under Wayland, the window icon is missing.

### Implementation description
Setting
[```GLFW_WAYLAND_APP_ID```](https://www.glfw.org/docs/latest/group__window.html#gafbf1ce7a4362c75e602a4df9e1bdecd3)
to fix the issue.

### Screenshots
Before:

![Screenshot_20240420_162144](https://github.com/WerWolv/ImHex/assets/71180087/3318970f-6ed7-4161-b686-c2eaa28a0739)


After:

![Screenshot_20240420_161920](https://github.com/WerWolv/ImHex/assets/71180087/e9e35fb6-e3c1-44a8-b7a5-b145dfe225d9)


### Additional things
<!-- Anything else you would like to say -->

main/gui/source/init/splash_window.cpp

@@ -415,6 +415,10 @@ namespace hex::init {
             glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 0);
         #endif
 
+	#if defined(OS_LINUX)
+	    glfwWindowHintString(GLFW_WAYLAND_APP_ID, "imhex");
+	#endif
+
         // Make splash screen non-resizable, undecorated and transparent
         glfwWindowHint(GLFW_RESIZABLE, GLFW_FALSE);
         glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GLFW_TRUE);

main/gui/source/window/window.cpp

@@ -720,6 +720,10 @@ namespace hex {
             glfwWindowHint(GLFW_DECORATED, ImHexApi::System::isBorderlessWindowModeEnabled() ? GL_FALSE : GL_TRUE);
         #endif
 
+	#if defined(OS_LINUX)
+            glfwWindowHintString(GLFW_WAYLAND_APP_ID, "imhex");
+	#endif
+
         glfwWindowHint(GLFW_OPENGL_FORWARD_COMPAT, GL_TRUE);
         glfwWindowHint(GLFW_TRANSPARENT_FRAMEBUFFER, GLFW_TRUE);
         glfwWindowHint(GLFW_VISIBLE, GLFW_FALSE);