FR: Make Union Base Types specifiable

[krojew]

trafficstars

Union discriminator (at least in Java) map to a single byte, which begins to be problematic when the number of messages exceeds the maximum range.,

[aardappel]

Yup, that holds in all languages, and is known problem.

It is hard to fix though, given the amount of code that assumes it's a byte.

[github-actions[bot]]

This issue is stale because it has been open 6 months with no activity. Please comment or this will be closed in 14 days.