Composer V2 support

Feature

• add support for Composer 2 [issues/59]
• allow patcher operations to be optionally disabled by re-declarng them with label replaced with: false

Maintenance

• introduce ready-to-use development environment setup for quicker developer onboarding [issues/65]
• improved linter rules to be a it less forgiving on excessive use of whitespace
• fix an issue where GIT applier was polled within the tests (due to there being repo-within-repo situation which made the applier to be excluded)

Links: src diff