feat: stats output

[GrantBirki]

Stats Output 📊

Currently, this cli runs with a spinner displaying very minor output as it goes for each repo. This is by design to keep the cli nice and clean (not a ton of cli spam/noise).

However, when it completes, the user doesn't really know what it did.

This issue tracks work to make the CLI have a nice "stats" output at the end and displaying links to any PRs it creates.

The "stats" output should be displayed by default with rich formatting and color. The color should be able to be disabled with a new --no-color flag and the entire "stats" output should be disabled with the new --no-stats flag.

Features:

• At the very end of the CLI run it stops the Spinner.
• A rich table/box/summary is displayed with what the CLI run did
  • What PRs got combined in what repo
  • What PRs were left out due to merge conflicts or other errors
  • What repos did not have enough matching criteria or PRs to actually generate a "combined pull request"
  • Totals of PRs combined on a per repo basis
• Links to the resulting "combined pr" per repo
• Supporting status about the CLI run (exec time, etc)