fix: Sign and Notarize MacOS App

[bdferris-v2]

Summary:

As tracked in #1200, this PR adds support for code-signing and notarizing the MacOS app. This will mean the user no longer has to ⌘-click the app to open it the first time. Note that they will still get the following warning when running the app for the first time:

But they can just click "Ok" and the app will run. I don't think there is any way to avoid that dialog without distributing the app through the Mac App Store.

Closing #1200.

• Run the unit tests with gradle test to make sure you didn't break anything
• Format the title like "feat: [new feature short description]". Title must follow the Conventional Commit Specification(https://www.conventionalcommits.org/en/v1.0.0/).
• Linked all relevant issues
• Include screenshot(s) showing how this pull request works and fixes the issue(s)

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1345 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1345 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
2 out of 1347 sources (~0 %) are corrupted.
Corrupted sources:
ar-buenos-aires-colectivos-buenos-aires-gtfs-1220
no-unknown-agder-kollektivtrafikk-as-gtfs-1078
Commit: 82e14e3
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1345 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1345 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
2 out of 1347 sources (~0 %) are corrupted.
Corrupted sources:
ar-buenos-aires-colectivos-buenos-aires-gtfs-1220
no-unknown-agder-kollektivtrafikk-as-gtfs-1078
Commit: ebe2933
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1347 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1347 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
0 out of 1347 sources (~0 %) are corrupted.
Commit: 93f5a6b
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.

[bdferris-v2]

Ok, made a last few tweaks. This is now ready for final review and submission.

[maximearmstrong]

Great work. Thanks so much @bdferris-v2! One small question before we merge.

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1352 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1352 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
1 out of 1353 sources (~0 %) are corrupted.
Corrupted sources:
ar-buenos-aires-colectivos-buenos-aires-gtfs-1220
Commit: faea014
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.

[maximearmstrong]

LGTM, thanks @bdferris-v2