feat(forge): --exclude-tests option from coverage

[grandizzy]

Motivation

• add option to exclude tests from generated coverage report
• keep default behavior, no breaking
• e.g. for morpho blue running without flag
  

vs running with --exclude-tests

Solution

PR Checklist

• Added Tests
• Added Documentation
• Breaking changes

[zerosnacks]

Hmm.. wasn't this already achievable through the forge coverage --no-match-coverage "(script|test|Foo|Bar)" filter introduced in #8321?

[grandizzy]

Hmm.. wasn't this already achievable through the forge coverage --no-match-coverage "(script|test|Foo|Bar)" filter introduced in #8321?

Yeah, but no-match-coverage happens only after the coverage / tests completed (so it basically collect source files / ast for test contracts as well and only after report is generated they're filtered out). With this PR the test sources are not processed / analyzed which should result in lower mem print and faster execution (didn't benchmark though)
I think both have they're own value, this new one for totally ignoring test contracts and no-match-coverage to customize the report (e.g. show only selected from src or test)