feat: add workflow-name-delimiter flag

[yorik]

what

Add workflow-name-delimiter flag to allow change delimiter in workflow name from default :.

why

To use something compatible with terraform-provider-github and avoid integrations/terraform-provider-github#1531.

tests

references

closes #3814

[jamengual]

I'm no so keen to add a workaround on the atlantis code because something else have a bug, I think we should wait until they fix it

[yorik]

I do understand that, but they fixing the problem since February: it will be breaking change for them unfortunately, so I thought that improve atlantis would easier for everyone.

[jamengual]

I do understand that, but they have been fixing the problem since February: it will be breaking change for them unfortunately, so I thought that improve atlantis would easier for everyone.

I get that, but who will then create the PR to revert this once this is fixed?

This is a Terraform issue on a provider which is 3rd levels down from Atlantis code, we can't use Atlantis as a workaround for code that Atlantis is not responsible for.

This is good documentation for other people with similar issues so they know why this happens.