Date consistency check for updates.csv and systemupdates.csv

[michihdeu]

The GitHub Action should check the date of new entries and fail if the date does not match the current day.

https://forum.travelmapping.net/index.php?topic=7771.msg43643#msg43643

[jteresco]

I like this idea. Hope to give it a try some time soon.

[cockroachking]

FPs should be allowed for editing existing entries (correcting spelling, broken links, etc.).

[jteresco]

Like the CCC, it's a change on check, so once it's merged it won't be an error any longer. No need for an FP mechanism beyond a note from the commit author saying it was intentional.

I think I'd want it to allow the current date or the day before.

[michihdeu]

Why day before? The check is executed when submitting the PR. Not on merging.
When the check fails, one minute after submission, I can immediately fix the date.
If one has to fix the route link or description, one can comment the failed check being FP