Create web UI

[mcmire]

The release process is arduous, and the CLI does not do a good job of helping users navigate through it. A lot of developers are more comfortable working with GUIs than command-line tools. A web UI could help dramatically improve the contributor experience with regard to creating releases for the core repo.

Acceptance Criteria

• When the developer runs create-release-branch, a new tab opens in the user's browser that displays a web UI. The UI presents a form that allows the developer to select which packages they want to release and how to bump those packages (much like the CLI today).
• If the developer deselects a package that ought to be included (because it has a peer dependency that was bumped, or because it is a dependency of another package) then the developer is informed immediately and is disallowed to submit the form unless they confirm they've checked there would be no impact (perhaps by selecting intentionally skip as an option, for simplicity, unless we can think of a better pattern).
• When the developer submits the form, the changes are applied and the developer is put on the new release branch. For each package selected, the version of the package is bumped accordingly and commit messages that have occurred since the previous release are copied to the changelog for the package (just like what happens now).