Add cockroachDB to EFcore CI

[ZhouXing19]

Fixes cockroachdb#1

[ZhouXing19]

@roji Hi! We made this PR to add cockroachDB to the EFcore CI. Thanks for reviewing!

We let the CI test against our v21.2.5 official release and the latest master branch. The main errors we are seeing are from SQL queries at test/EFCore.PG.FunctionalTests/Northwind.sql:

• For v21.2.5, we saw error message the configuration setting "check_function_bodies" is not supported. We add support for check_function_bodies one month ago in the master branch, but this is not in an official release yet.
• For the master branch, we saw error message unimplemented: extension "uuid-ossp" is not yet supported.

For more details about the failed tests, please check here.

cc @rafiss

[AraHaan]

Nice, but does cockroach support things like Views and Table Triggers by chance (as some might want triggers for cases like insert where they got to merge old values with the new to update, insert, and delete all at once)?

I am asking because I am considering using cockroach for my Discord Bot and ditching sql server that is locally on my pc.