[VDG] Refactor navbar

[soosr]

Based on #9724, draft until that one gets merged.
Fixes: #8249

The main problem with the NavBar was that it was a ListBox and we relied on its SelectedItem property. That property was the trigger of the navigation.
This logic got problematic at a point as there are items in the NavBar that cannot be selected, so the idea is to have Buttons instead of the ListBoxItem in the NavBar, and the trigger of the navigation is the click that executes a command.

This PR:

• Removes many negative margins and unnecessary code from the AXAML.
• Removes the workarounds
• Simplifies a lot

Known issue:

• Navigation to another wallet B as soon as wallet A started to load breaks the navigation, the following PR will fix (including other fixes)

[soosr]

Don't merge it before release.

[nopara74]

LGTM, id like @wieslawsoltes also to take a look

[wieslawsoltes]

LGTM

@soosr We can remove NavBarListBox as it's not used anymore.

[wieslawsoltes]

LGTM

@soosr We can remove NavBarListBox as it's not used anymore.

#9905