In-Game: Add an "is_instance()" for checking instance ids, following changes in 2022.6

[iampremo]

Ticket #200200

The recent runtime update changed instance ids to no longer count for any of the "is_" functions except for "is_numeric". Having an "is_ref" function would be useful.

Benefit: Checking "is_ref" would be faster than checking for "isnumeric" to be true, and then checking [all] the other "is" number functions to [make sure they are also] false.

[KeeVeeGames]

There is is_handle function available now.