We need to have root packages for module xml files in plugin model v2, but if we specify packages with real classes in these modules, they'll fail to load with "must not be requested from main classloader" error, because inter-module dependencies aren't specified for these files. If we specify module dependencies, the big 'com.intellij.java' plugin will fail to load because it isn't migrated to plugin model v2 yet and includes contents of these module descriptors via xi:include tag. So it seems that we need to use fake packages without real classes until 'com.intellij.java' plugin is migrated to plugin model v2.
Check in InterfaceExtensionImplementationClassResolver is suppressed for 'com.intellij.java.frontend' plugin as well for now.
GitOrigin-RevId: 7b2321835becc9f4589ddae09a40160bf735044e
remove unnecessary dependency on kotlin serialization module from `intellij.platform.core` module (it is an OpenAPI module, some test failed)
move all changes from `intellij.java.frontback.psi` module to `intellij.java.frontback.psi.impl` module so that there will no be a dependency on kotlin serialization modules in the `intellij.java.frontback.psi` module because `intellij.java.frontback.psi` module is an OpenAPI module (some test failed)
(cherry picked from commit a3fa1ab533734442fb6691b0162b3f930a66d9bc)
IJ-MR-116786
GitOrigin-RevId: 81bf0153f9528d9ec58e6b557fa0b7aee80a2c46
