Psre 2138/feature/pre hash string utils PSRE-2229

[shtrom]

This PR:

• introduces a separate PreHashString service concept, and moves the current implementation into a LegacyPrehashStringService
• removes the ability to inject signature factories into the Init object, as using the latest version is a deliberate choice
• reintroduces v1 signature tests
• moves the tests params to a separate fixture provider
• ensures that things we want to test for backward compatibility are hardcoded strings, rather than generated on the fly
• refreshes the phpunit config
• adds linting tools
• lints the lot for good measure
• add a github workflow to run those tests on PR

It may help to review this PR commit by commit, as they build on top of each other.

Checklist

• [x] Feature

• [ ] Bug

• [x] Refactor

• [x] ChangeLog.md updated

• [x] Tests added

• [x] All testsuite passes

• [x] make dist completed successfully