map: share some code

map: share some code

Make more extensive use of get_entry_for_key_state, and add
key_get_consumed to use in the other consume functions.

There's also a slight change in the consumed mods calculations, where
we use entry->mods.mask instead of type->mods.mask. The original was
copied from what libX11 does but what we do now is more logically
correct. The result is exactly the same though because:
type->mods.mask ⊇ entry->mods.mask ⊇ entry->preserve.mask

Signed-off-by: Ran Benita <ran234@gmail.com>