[devtools] Add update license command

[mossmana]

Adding a command to dt to update licenses.

#8216

Please add a note to packages/devtools_app/release_notes/NEXT_RELEASE_NOTES.md if your change requires release notes. Otherwise, add the 'release-notes-not-required' label to the PR.

Pre-launch Checklist

• I read the [Contributor Guide] and followed the process outlined there for submitting PRs.
• I read the [Tree Hygiene] wiki page, which explains my responsibilities.
• I read the [Flutter Style Guide] recently, and have followed its advice.
• I signed the [CLA].
• I listed at least one issue that this PR fixes in the description above.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or there is a reason for not adding tests.

![build.yaml badge]

[kenzieschmoll]

these look like changes from another PR. Can you merge with master so that these changes are removed from the diff?

[mossmana]

This will be updated to a more generic path if/when we decide to merge this. Right now, using this to run locally and don't want to lose my changes.