Add a briefcase template to pygame-ce

[Starbuck5]

This is similar to the PyInstaller hook we have, but for Briefcase, another distribution solution. (https://beeware.org/project/projects/tools/briefcase/)

The template and strategy are largely copied from the existing entrypoints in the briefcase library.

Worked on this during the Beeware sprint at Pycon US 2024.

I think this supersedes beeware/briefcase#1804

To test, install briefcase with pip, install pygame-ce from this branch, and run briefcase new. After going through the briefcase options, it will have a "GUI Framework" option that will now report pygame-ce as an option. This works as a template for pygame-ce in briefcase, but is not necessary for supporting distributing pygame-ce apps in briefcase.

After this PR (in briefcase new):

-- GUI Framework -------------------------------------------------------------

What GUI toolkit do you want to use for this project?

  1) Toga
  2) PySide6       (does not support iOS/Android deployment)
  3) PursuedPyBear (does not support iOS/Android deployment)
  4) Pygame        (does not support iOS/Android deployment)
  5) pygame_ce     (does not support iOS/Android deployment)
  6) None

[oddbookworm]

LGTM! I just have one small thing that might be fine to remove

[MyreMylar]

OK, LGTM 👍

Tested it on my machine and got a hello world briefcase test program running.

[ankith26]

I just went through the process of created a .deb package, and it went really smooth! I'm really starting to like this tool.

[robertpfeiffer]

Does the .deb depend on pygame-ce, or does it bundle its own SDL, pygame, and so on?

[ankith26]

It bundles the stuff in the pygame-ce manylinux wheel (so in a sense it is a self contained deb-file that doesn't use system dependencies, which is not very deb-file like)

If a pygame-ce debian package existed, we could make it depend on that, and that would remove the need for copying/duplication of pygame-ce

[ankith26]

This PR has my approval. Even though I left a question, I feel it's better to merge this in for 2.5.0 anyways, as we can polish this up in future releases.

[oddbookworm]

Does the .deb depend on pygame-ce, or does it bundle its own SDL, pygame, and so on?

I think it is completely self-contained, I might do some testing later with a couple of ubuntu VM's that don't already have things installed