KT-5522 Rename refactoring on implicit lambda parameter 'it' should be allowed

 #KT-5522 fixed
Moved "Copy as Diagnostic Test" to Tools -> Kotlin.

Renamed class and done some cleanup.
"Copy as Diagnostic Test" is visible only in internal mode.
KT-5531 Introduce separate 'kotlin.internal.mode' property and use it to trigger red/black rectangles and debug information in error tooltips

 #KT-5531 fixed
Added test for KT-1735 Can't access "assert" function from stdlib

#KT-1735 fixed
Fixed collecting source files for multiple modules in incremental compilation.

Error led to analyzing same file twice.
Enabled Kotlin internal mode in JetPsiChecker tests.
Enabled Kotlin internal mode in IDEA run configurations.
Reverting internal mode state in tearDown of JetPsiChecker tests.
Boxing values merge fix. #KT-5588 Fixed

When merging Boxed value and something else just return MIXED_VALUE
Enabled inlining and optimization in bytecode tool window by default.
Simpler byte code generated for comparison with null and zero.

Analogous byte code is generated by Javac.
JS backend: add NotNull annotations
JS backend: convert PropertyTranslator to Kotlin
JS backend: support for explicit delegation

 #KT-4479 Fixed