Approved merge requests, config improvements...

• Support custom xmlrpc endpoint for MoinMoin wiki
• Adjust the approved merge requests for gitlab
• Add search for approved merge requests in gitlab
• Enable copr builds from master, simplify tests
• Add "no prefix" rule to commit message suggestions
• Simplify packit config, enable epel-8 for testing
• Do not use interpolation for ConfigParser
• Expand tilde in config path values
• Fix a typo in the README format section
• Update test data for the gerrit plugin
• Adjust password file support for jira & confluence
• Add password file options for jira and confluence