bug(mac): OSK not opening on activation for some keyboards

[sgschantz]

If the OSK is open when switching from Keyman to a different input method, then it should close automatically. When switching from the input method back to Keyman, the OSK should automatically open again. This happens for some keyboards, but for others it does not.

For example, this works correctly for the Khmer Angkor and Polytonic Greek keyboards but fails for EuroLatin (SIL), phonetic_farsi and
IPA (SIL). The common factor among the failing keyboards is that they do not include KVK files.