Externally tagged enums

[lukaszlew]

I added support to externally added enums for typescript (I did also most of other langs, but for first PR TS only).
I wanted to create PR but then I noticed typeshare2 refactor.

I need that feature urgently because many serialization libraries (e.g. postcard, message pack) do not support well adjacent enums.

What should I do?
I tried to move to ts-rs and some other libs, but failed for other reason.

I guess the question is, when typeshare2 will become merged and when you start accepting contributions again.

[lukaszlew]

I could port my change to the typeshare2 branch ...