[feat] browser - rebuild thumbnails menu item state

[user0]

XnViewMP 1.4.5 64bit
Windows11 (22H2), display resolution 3840x2160, win scaling 150%

Browser
'Rebuild thumbnails' menu item always enabled, even when it or parent Catalog are disabled in Settings.

Similar to already fixed issue:
1.3.1 - browser - Catalog related functionality remain enabled when Catalog is disabled in settings (fixed in 1.4.3)

[xnview]

you can rebuild thumbnails even if catalog is not used

[user0]

right, I missed that point