Rename the spacetimedb-quickstart and spacetimedb-quickstart-cs modules

[cloutiertyler]

https://github.com/clockworklabs/SpacetimeDB/tree/master/modules/spacetimedb-quickstart
AND
https://github.com/clockworklabs/SpacetimeDB/tree/master/modules/spacetimedb-quickstart-cs

serve an unclear purpose. In the interest of clearly defining support and testing requirements, I propose that we rename these modules to:

module-test-rs
AND
module-test-cs

Additionally the code from rust-wasm-test should be transferred verbatim (or as near to verbatim as is possible, lest we have a regression) into module-test-rs and translated into module-test-cs.

rust-wasm-test should then be removed.

[bfops]

I agree with the goal here, but it seems not-blocking for 1.0 release? Couldn't this be a priority for our testing pass?