Plugin for limiting the number of consecutive skips or postpones

[undefiened]

I added plugin which allows to limit the number of consecutive times one can postpone or skip break. This is a middle ground between the strict mode which completely disables the skipping/postponing feature, and being able to click skip/postpone indefinitely. There is only one setting which tells how many times in a row one can skip breaks.

When user has skipped X breaks consecutively (without taking any breaks) both skip and postpone buttons become disabled.
Taking break completely (without skipping or postponing) resets the counter.

This should somewhat address #320. At the very least it addresses @tuhlaajapoika suggestion #320 (comment) (I also happened to have ADHD, so what @tuhlaajapoika described was exactly my problem: I was automatically clicking skip without even thinking).

There was no existing mechanism which would have allowed me to remove both buttons without making any changes in UI or core, so I added two flags to "context" and added some logic to UI. The intention behind these two flags is to simply disable both buttons for the next break, after which both flags become reset back to False. Not sure if it is the best solution, so if you have some better mechanisms in mind feel free to let me know and I will do it.

Also, I am not sure about wording of settings and plugin hints, so I would appreciate any suggestions.

[undefiened]

Dear @hartwork and @slgobinath, I looked at the previous PR's and noticed that you are usually the people who resolve them. I just wanted to mention your usernames to make sure that you are aware of this pull request. There is absolutely no time pressure from my side, I'm just making sure that you are aware of this PR in case you didn't receive any notifications.

[slgobinath]

Hi @undefiened ,
Thank you for your contribution. Sorry for the late response I got busy with my life and have little to no time for my FOSS projects.
I didn't get a chance to test it but the code looks good to me. Can you please add an icon suitable for this plugin as described here https://github.com/safeeyes/safeeyes-plugins#best-practices ?

FYI: The new URL to download font awesome icons is https://fa2png.app/

[undefiened]

Added an icon. I didn't find anything suitable, and 24x24 is a rather limiting size, so I did my best. If there are any better ideas, I will be happy to incorporate them.

No worries at all about not having time, it was not my intention to hurry you, I just was not sure how GitHub notification system works. Please take as much time as needed to reply and review. Thank you very much for all your hard work!

And thank you for giving a link to the safeeyes plugins repo, I somehow missed it in the description. Should I move my plugin to the safeeyes-plugins repo? If yes, then I probably should make two separate PRs, one here to modify the core stuff and one in the third-party plugins repo. Or is it fine to have the plugin here?

Also, I removed the copyright with your username from my plugin.py (I have copypasted the header from your other plugins, so it included your copyright). But I can return it back if needed, I don't really understand the logic of licenses and copyrights, I am happily giving up all my copyrights (if I ever had them) or whatever.