When the user selects all of the types or none of them, the "types"
property must be set to a special value (`NET::AllTypesMask = -1`),
different than the sum of all the flags together.
This re-implements this behaviour as the old KCM, fixing some heuristics
that prevented finding the rule corresponding to the current window.
The enum name that handles this property has been changed to `NetTypes`
to make it more explicit.
BUG: 423214
FIXED-IN: 5.19.3
TEST PLAN:
1. Open the `Application specific settings` on a window via menu
2. Select every "Window Type" (or none of them)
3. Give the rule a different name than the default and save
4. Open it again and check that the same rule is found
8b9472e0bf