[Feature request] pw field when adding / changing password should indicate whether CAPS-LOCK is on

[zetok]

Brief Description

Currently only login page shows indicator of CAPS-LOCK being on when typing password – it should be available also when changing / adding a password on profile page.

Reproducible: Always

Steps to reproduce

1. Turn on CAPS-LOCK
2. Click on Add / Change password on profile page

Observed Behavior

Password filed doesn't have caps-lock indicator

Expected Behavior

CAPS-LOCK indicator should be shown

Additional Info

Related: #3245

[b4n]

Same applies to the "load profile" login screen field. Only the "New profile" fields show a capslock warning.

[b4n]

I've got a fix for that, but I made it on top of #3383 because it changes API, so I'd rather wait for that one to be dealt with first.

However, it's not as pretty as I'd wish it would be. Ideally, I guess we should have a custom QLineEdit widget for passwords that does it itself, but:

1. I don't know if it'd be possible to use to from .ui definitions?

2. I failed to find an encapsulated way to get notified when capslock changes. Current way (from feat(loginscreen): Added CapsLock indicator #3257) is on the ::event() virtual method on the top level (window), so that's not very encapsulated.

   Encapsulating would be interesting even without 1 above, because it would avoid the need for a caller to manually call ::updateIndicator().

But as I'm totally new to Qt, maybe someone more experienced would know.