More comprehensive CI coverage

[ian-h-chamberlain]

Right now, the CI only does two basic functionality checks of the tool:

      - name: Create new project
        run: cargo 3ds new app --bin

      - name: Build project
        working-directory: ./app
        run: cargo 3ds build --release

We could add more unit tests, integration tests, etc., but it would probably be a good idea to just run through some of the different uses cases that are supported. Offhand these are the ones that I can think of:

• cargo 3ds build maybe with a couple of other argument combinations
• cargo 3ds test (with and without --no-run)
  • --lib
  • --doc
  • --test ?
  • --example? is that supported?
• cargo 3ds run
  • --bin
  • --example
• cargo 3ds doc, I guess? Maybe also other passthrough commands like check, clippy, etc.

We'd probably need to use custom runners or a custom 3dslink wrapper script to really test everything properly.

Also would be nice to test on different platforms, but the lack of devkitPro toolchain images will probably make it hard to test the whole process. We should bbe able to at least test cargo 3ds new and maybe cargo 3ds check?

[Meziu]

When those simple tests were added ther was no way to run code in the CI. I guess we should expand the suite now that we can 👍.