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.