Ctrl+click navigation added.

 #KT-5366 Fixed
Minor: OpenEditor string is now a constant string in OpenDeclarationAction class.
Issues from comments fixed.
Minor: Java code conventions.
Methods for autotesting added to KotlinEditorAutoTestCase.
SourceFileData splitted and moved to KotlinEditorAutoTestCase.

All TestCase classes are now abstract.
AllTests class added for completion tests.

Minor: code conventions
Tests for navigation performed.