Add Matt Boyer as a codeowner to all Automation & Tooling packages

Adding @matt.boyer as a codeowner to all packages associated with the Automation & Tooling mission team.

Other minor things:

• Added a new-line to the end of CODEOWNERS file on the repos that had it missing.
• Created an icon-decorator label for the Icon Decorator tool, since it was missing.
• This issue is missing an addition to the renovate-runner package, since there is no CODEOWNERS file there. Will create the file and include myself through another issue.