HCPE-926 - Add github checks for depscheck, fmtcheck, and gencheck

[roaks3]

🛠️ Description

Added GitHub checks (and make targets) for:

• depscheck - Run go mod tidy and make sure there are no differences
• fmtcheck - Make sure gofmt has been run on all Go files
• gencheck - Run go generate and make sure there are no differences

I chose these checks to start since they don't require any additional tools to run. Also note that there is no cache being used here, so that might be something we want to look at if these checks start taking a long time to run.

For reference:

• AWS provider gofmtcheck.sh, makefile, and CI checks
• Kubernetes provider gofmtcheck.sh, makefile, and CI checks

🏗️ Acceptance tests

• Are there any feature flags that are required to use this functionality?
• Have you added an acceptance test for the functionality being added?
• Have you run the acceptance tests on this branch?

Output from acceptance testing:

$ make testacc TESTARGS='-run=TestAccXXX'

...

[bcmdarroch]

Yaaa! 🙌