feature: add measure option and optimise LCOV parsing

[mrexox]

Also update LCOV tests and filesCloses

:zap: Summary

• [x] Use only data from LCOV coverage, don't read through source files
• [x] Add -m/--measure option to measure time for parsing and request (can also be enabled with --debug option)

:ballot_box_with_check: Checklist

• [x] Add specs

[coveralls-official[bot]]

Pull Request Test Coverage Report for Build 5532352819

• 16 of 18 (88.89%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+1.3%) to 93.644%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/coverage_reporter/reporter.cr	9	11	81.82%
<!--	Total:	16	18	88.89%	-->

Totals
Change from base Build 5531263170:	1.3%
Covered Lines:	884
Relevant Lines:	944

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💛 - Coveralls