Improve the type checking for node fields that accept multiple value types

[TwitchBronBron]

#1191 provided relief for some of the pain points of node fields that accept more data types, but ideally we could improve many of these field types to accept a subset of values. For example, translation can only accept a string literal value that looks like an array, an array, or perhaps a variable of type string (when we don't know what the value actually is). We should do more extensive testing to find all the edge cases for these fields, and improve the type system accordingly.