v1.8.0

Overview

1. Simplify Rule interface by removing Severity()

Updates

1. ci: gh actions: add workflow_dispatch
2. enhance: openapi3lint: remove Policy.rules
3. reorganize: openapi3lint: split files
4. rename: openapi3lint: rule_collection.go
5. style: openapi3lint: gofmt -s
6. refactor: openapi3lint: remove Rule.Severity() from interface
7. feat: openapi3lint: add PolicyViolationsSets.CountsByRule()