MPS-20692
tests for MPS-20692
MPS-20723
fix possible NPE, fix tests
fix tests
Merge remote-tracking branch 'origin/master' into simonBug

Conflicts:
	languages/baseLanguage/baseLanguage/source_gen.caches/jetbrains/mps/baseLanguage/generated
	languages/baseLanguage/baseLanguage/source_gen.caches/jetbrains/mps/baseLanguage/migration/generated
	languages/baseLanguage/baseLanguage/source_gen.caches/jetbrains/mps/baseLanguage/typesystem/generated
	testbench/tests_gen.caches/jetbrains/mps/tests/generated
rebuild, add ITestCase
rebuild base language
gen runner
Merge remote-tracking branch 'origin/master' into simonBug
fix tests
Merge remote-tracking branch 'origin/master' into simonBug
fix tests
generate