Add mima checking

[IvanFinochenko]

Issue #750

[grouzen]

@IvanFinochenko Hello! Thanks for the contribution!

A few questions/suggestions.
I believe this PR is missing the CI part to run the check, which is a mimaCheck alias you've added.
This can't be done via amending ci.yml directly since we're using sbt-zio plugin that generates it for us. It means we must use one of the available sbt-zio directives to include the mimaCheck command in the CI pipeline.
After doing this, we just need to set mimaFailOnProblem to false until we release the 3.0.0 version.
That's just how I see it. I hope it makes sense.

[IvanFinochenko]

@grouzen Hello! Thanks for suggestions.
I have fixed it.