nyx: add password lock

[paulober]

This PR adds a simple password lock to nyx. The password is currently stored in plain-text in the nyx.ini config.
It's fully functional but there may be some code that can be shared between the gui.c and gui_options.c.

This feature is mainly intended for modchip switch models to prevent others from accidentally tampering with your config or getting you banned because they aren't into switch modding.

[CoderQCYT]

this will be amazing for siblings

[CTCaer]

I already talked about such a thing and how easy it is to bypass.
I will add a reference label for anyone that believes his kids will not think to google or change/edit the sd.

[CoderQCYT]

My friend barely Googles any of his computer problems, he just asks me, and I end up googling them for him.
Plus, not everyone is smart enough to:

• Take out the SD card and insert it into the computer, navigate, and change the file. (I've had lessons in school solely around doing this, I thought they were redundant, but no, apparently not)
• Reinject the payload to the Nintendo Switch. I don't know anyone else close to me who can do this.

And even if all of this is easy, most people won't spend the time and effort. They're probably just going to stop trying because of "fear of breaking something". Normal locks are like this too. Could you just throw an axe through the front door? Yes, you could. Would most people do that if they wanted to get in? No, they wouldn't.

[CTCaer]

Well 99.9% of the Switch users just visit NH discord. There, they will just get the exact steps to fix it.
Should Nyx get bloated with this because of the rest 0.01%? The answer is no.
Plus the traffic it can cause here with "My switch asks for a password" or "I got locked out" is not worth it.

Anyway, I will reopen the PR. For sure it needs changes. Like styling or the use of TA (a label is enough) from a cursory look.
But will review it fully after the next release.
(The 2 issues btw were closed because this PR is a direct descendant of them.)