Add ability to get diagnostic information from app-build-verify and app-create-verify actions

### What is the problem or limitation you are having?

When developing beeware/briefcase#2241, I hit some errors during the CI invocation `briefcase create` process that I couldn't initially explain. However, as briefcase is invoked non-verbose, and logs are not preserved, it was difficult to diagnose the source of the error.

### Describe the solution you'd like

1. If a CI run is invoked in debug mode, `-vvv` should be added to the briefcase invocations for the `app-create-verify` and `app-build-verify` actions.
2. Any log file produced during failed runs should be attached to the CI run for diagnostic purposes.

### Describe alternatives you've considered

An alternate approach would be to expose configuration points in the app-build-verify and app-create-verify action that enable injecting additional command line into calls to briefcase. However, `-v[vv]` are likely the only options that an end user is likely to want to invoke.

### Additional context

_No response_

Locate the app-create-verify and app-build-verify GitHub Actions and inspect how they invoke briefcase and handle failed-run logs. In debug mode, the briefcase invocations should include -vvv, and logs from failed runs should be attached to the CI run; verify both actions satisfy these outcomes.

Written by the indexing model from the issue text.