Adds a "Skip gap on top screen edge" checkbox in Settings

[GVonB]

Change Description:
Currently, window gaps apply underneath the MacOS menu bar. On displays without a notch, this can create a larger perceived top margin relative to the other screen edges.

This PR adds an optional setting to exclude the top screen edge while preserving the gaps for the other sides and between windows.

Default behavior stays the same.

Original behavior, applying padding under menu bar:

Behavior with top edge gap disabled:

Settings Menu:

[rxhanson]

Thanks, I like it!

• I was trying to think of a better label for the checkbox, maybe something like Remove gap on top screen edge
• What are your thoughts on tailoring this specifically to notchless displays? We could then make this something like Remove top gap on notchless displays. There is some existing logic in Rectangle for determining if the display has a notch or not, which could be leveraged. It's for specifying the gap on the display with a notch as opposed to removing it. I could see rolling in another change where a slider for this is also added.

[GVonB]

• I was trying to think of a better label for the checkbox, maybe something like Remove gap on top screen edge

I definitely thought the wording was strange as well. Originally I had Apply gap under menu bar, but that would imply the box should be checked by default to preserve current behavior. I will switch it over to Remove gap on top screen edge

Personally, I think keeping the option as a simple toggle rather than notch detection is a better option at least for now. I found that I still preferred the top-gap removal even on my notch display, so if Remove top gap on notchless displays were to be added, it might make sense to make that a separate toggle to leave the option open.

Of course, up to you and I can adjust the PR in whatever direction you prefer.

[rxhanson]

I agree and I prefer the simplicity as well. Thanks again!