feat: Initial entry for @GtfsValidationNotice annotation

[bdferris-v2]

As part of on-going work for #1324 for automatic generation of notice documentation from source code, this PR introduces @GtfsValidationNotice, an annotation that will be used to configure and document validation notices in source code.

As generally described in https://bit.ly/gtfs-validator-notice-documentation, this annotation will be applied to all ValidationNotice classes in a follow-up PR. It will then be used as run-time to resolve a notice's severity and also to generate documentation for the notice.

I'm introducing the annotation in its own PR so that we can confirm the API before I do the large-scale transformation of the code-base to add it. I do include documentation for one notice as an example of its usage.

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[davidgamez]

LGreatTM!

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
New Warnings: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Warnings: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
0 out of 1423 sources (~0 %) are corrupted.
Commit: 3a4e105
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.

[bdferris-v2]

As an FYI to @isabelle-dr in case you have any feedback on the proposed design.

[bdferris-v2]

I discussed this offline with @davidgamez but I have proposed a refactor to where some key annotations and entity interface are stored (#1362) that will breakup a potential circular dependency. Critically, we want to use the new @GtfsValidationNotice annotation for notice processing, but there are already notices defined in core. By putting the annotation there as well, it limits our ability to do that processing from a Gradle module standpoint.

I have proposed moving the annotations into their own module. I think this has some nice properties down the road for splitting up our model API and our business logic, so I think it's a net win. I will update this PR based on the refactor PR.

[github-actions]

✅ Rule acceptance tests passed.
New Errors: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
New Warnings: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Warnings: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
0 out of 1423 sources (~0 %) are corrupted.
Commit: 06b01cd
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 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Errors: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
New Warnings: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
Dropped Warnings: 0 out of 1423 datasets (~0%) are invalid due to code change, which is less than the provided threshold of 1%.
0 out of 1423 sources (~0 %) are corrupted.
Commit: 73c4804
Download the full acceptance test report here (report will disappear after 90 days).
✅ Rule acceptance tests passed.