DFA fixes: special "null" nullability; flush on end of field initialization; always transfer from temp variables

Solves problem with duplicated messages in builds

This fixes IDEA-116425 and related IDEA-148109

IDEA-204717 Can't convert enhanced 'switch' to 'if' if a branch's body contains an end-of-line comment

[external annotations] process module-level libraries when looking from provided annotations locations

Implementations are expected to provide Maven coordinates to retrieve external annotations artifacts, if applicable.

This reverts the commit "vcs: cleanup: rollback adding wildcards in cases when they introduce yellow code".
It was decided that a better API is more important than a couple of class casts in implementation.

This reverts commit e0608d6a
Follow-up: c3d946be
Discussed in IDEA-CR-41615

IDEA-203743 Test result tree is not showing fail when cucumber step contains a single quote

IDEA-204749 Dialog Wrapper ComponentValidator API should allow me to use two separate validators on text change and on focus lost