Added typecheck for the registry tags

[moupriyaroy25]

Small changes to add type check for registry tags to check if registry_tags is a valid Dict[str, str] parameter.
the registry tags are in a dictionary format like this:

{"description":"this is a test feature"},so valid dictionary parameter.
and if the user does something like this

{"description", "this is a test feature"}, it'll also validate it.

[hangfei]

Thanks for the PR. Could you add a few tests for this?

Also maybe test dicts that contains non-string objects, like {"apple":[list of things]}

[moupriyaroy25]

@hangfei Thanks for reviewing. While I am trying to run the tests I am facing some issues during the installation of feathr module on my system. Here is the issue I have mentioned https://stackoverflow.com/questions/72316535/confluent-kafka-install-error-error-legacy-install-failure

[moupriyaroy25]

@hangfei could you please also elaborate briefly about adding test dicts? Do I need to add any test files for this? I am still so new in this case so adding some links to reference docs might help me figure that out.