[BUG] Add support for local accounts

[mrdvojo]

Describe the bug
After 2.1, local account name is not displayed in user-module on top bar, as I did also report on discord but posting it here too, since it is still not fixed after couple of updates that were these past days.

To Reproduce
Steps to reproduce the behaviour:

1. Use local account
2. Instal Seelen UI

Expected behaviour
Well it should show name of the local account as it did before the rework of user-module

Screenshots

[luriusTM]

Ok. First, local accounts works.

It does not have display name configured, so you get back empty formatted string from winapi, which is correct.
This can be fixed with username instead of display name.
Altough a possible fix for this can be:
https://learn.microsoft.com/en-us/windows/win32/api/secext/nf-secext-getusernameexw

Image works, but as much you never set up an image, the settig not exists, so it could show this (as it is), or the original fallback image, which is located:
C:\ProgramData\Microsoft\User Account Pictures\guest.*
Or can show an icon as none is there.

[luriusTM]

Currently as I saw the code have removed the observation for local property changes, so you got to restart Seelen to the modification take effect