Also copy searchable options indices for v2 modules #SCL-25004 fixed

[tests] extract common logic to SbtIdeaPluginIntegrationTestBase and don't clean cached SDK by default

[run configurations] differentiate between run/test customIntellijVMOptions in generated junit run configuration template

[tests] add debug agent VM option to sbt process in tests

mute deprecation warning in editor as workaround for SCL-25104

disable "Deprecation" inspection as it effectively duplicates another Scala-specific inspection 'Scala deprecation' in Scala files (see SCL-21525)

Document packaging vs structure PackagingMethod split in ScalaDoc

Fix MergeIntoParent warning heuristics and document fallback

downgrade plugin dependency "duplicates" from warning to debug level to reduce noise

Install unbundled plugin dependencies into dev IDE #SCL-23786 fixed

[vm options] use $IDE_HOME on linux instead of $IDE_HOME% in ProductInfoExtraDataProvider

[vm options] filter out the -Djava.system.class.loader=com.intellij.util.lang.PathClassLoader option from the test VM option

use separate system and config directories while building searchable index

[run configurations] remove a redundant "Build" step before launch, just leave the "Build Artifacts" step

[vm options] refactor the way how VM options are constructed for the IDE process (for dev IDEA and tests) (#SCL-24313, #SCL-23540) fixed