feat: adding array and regex support to deleting a state

[dirkbolte]

• add contexts parameter to deleteState
• add contextsMatching parameter to deleteState
• cleaned up DeleteStateEventListenerTest
• fixed display issues in README

References

68

Submitter checklist

• [ ] Recommended: Join WireMock Slack to get any help in #help-contributing or a project-specific channel like #wiremock-java
• [ ] Recommended: If you participate in Hacktoberfest 2023, make sure you're signed up there and in the WireMock form
• [ ] The PR request is well described and justified, including the body and the references
• [ ] The PR title represents the desired changelog entry
• [ ] The repository's code style is followed (see the contributing guide)
• [ ] Test coverage that demonstrates that the change works as expected
• [ ] For new features, there's necessary documentation in this pull request or in a subsequent PR to wiremock.org