Move tagged collections/modules to separate assembly #43
Description
ExtCore has some features requiring the library to be built using the F# proto-compiler (fsc-proto), most notably the 'tagged' collections types (such as TagMap) and their supporting modules. I've found these collections to be extremely useful in practice, so I don't want to get rid of them entirely; the requirement of using fsc-proto to build ExtCore is painful though, and makes maintenance much more difficult.
I was thinking of ways to more-easily use fsc-proto in CI builds (e.g. with a docker image), but upon reflection I think the most straightforward way forward will be to move the tagged collections into a separate project/assembly (e.g. ExtCore.TaggedCollections) which references ExtCore proper. That won't eliminate the fsc-proto requirement, but it does allow ExtCore to be updated separately -- we can work out a better solution (maybe) for building the ExtCore.TaggedCollections project later.