Enhancement: Add Step Functions to support resourcegroupstagging

[zkarpinski]

Per the AWS docs Step Function support the Resource Groups Tagging API.

It looks like there is a custom implementation for tags for step functions. @bblommers is there a special case with Step Functions or is this a simple use-case to add this support?

[bblommers]

Hi @zkarpinski, that should be relatively straightforward.

The Resource Groups Tagging implementation in Moto simply checks the backend for each service, and uses the tags already stored there. So it would be a matter if adding an additional logic-block for SFN here:

moto/moto/resourcegroupstaggingapi/models.py

Line 205 in c6aea52

# ACM

[zkarpinski]

@bblommers Easy enough thank you for the guidance. Submitted a pr!