Support scope type for members of type disjunctions in Typescript

[pokey]

For example

type Foo = Bar | Baz | Bongo;

We'd like to be able to say eg "take item bat", to select Bar, or "take every item bat" to select all 3, and would like to clean up | on removal. Not sure if we want to call this one "item" or something else. Would prob want to impl this one after / as part of #825

Also note that impl might be a bit similar to #707 due to car/cdr-style parse tree