feature: create PR with `gh`

[Necrom4]

Did you check the docs?

• [x] I have read all the snacks.nvim docs

Is your feature request related to a problem? Please describe.

Lately I discovered LazyVim's extra gh.nvim which I loved, but was too much focused on reviews, so I then tried the extra octo.nvim, which has lots of commands but does not integrate well with snacks' picker. Snacks' new gh integration is much cleaner and intuitive (thx for the amazing work!) but is missing a few features I use a lot, such as creating PRs, displaying check logs and notifications.

Describe the solution you'd like

Running a command such as Snacks.gh.pr.create() asks for input (the usual information: name of PR, branch to merge into, etc), creates the PR and opens it in a buffer.

Describe alternatives you've considered

Using :Octo pr create, gh pr create in the terminal or GitHub.

Additional context

No response