Allow pattern matching by CLI for --tests argument with test command

[big-kahuna-burger]

So we don't have to do these loops in GH Action like here:
https://github.com/openfga/action-openfga-test/blob/main/action.yml#L27-L38

Right now, it's not possible to do something like this:

fga model test --tests=./*.fga.yaml 

or something like this:

fga model test --tests=./**/*.fga.yaml 

This would enable us to write better test suites, since we could get some naming conventions out, and run them as scenarios with separate tuple sets more easily