wip: experiment find file

[vladopajic]

this pr add new method for finding files by listing all .go files from current directory and matching it to paths from coverage profile.

effort for #139

[github-actions]

go-test-coverage report:

File coverage threshold (100%) satisfied:	FAIL
  below threshold:				coverage:		threshold:
  pkg/testcoverage/coverage/cover.go		97.9% (143/146)		100%

Total coverage threshold (100%) satisfied:	FAIL
Total test coverage: 99.5% (609/612)

Files with uncovered lines:
  file:					uncovered lines:
  pkg/testcoverage/coverage/cover.go	173-175 189-191 202-203

Current tests coverage has changed with 3 lines missing coverage.
  file:					uncovered:	current coverage:	base coverage:
  pkg/testcoverage/coverage/cover.go	  3		97.9% (143/146)		100% (120/120)