add a gitrepository name parameter to the flux_bootstrap terraform resource

[0x6a77]

the flux_bootstrap terraform resource is a huge leap forward!

after migrating two clusters to it, one big, and easy, improvement would be to add a gitrepository name parameter (instead of getting it from the namespace). the way it is now, if a cluster has more than one repo then each gitrepository has to go into its own namespace and you end up with a set of controllers in multiple namespaces. (in the documents-based terraform resources we are able to have one set of controllers in namespace flux-system even with multiple repos).

[0x6a77]

a quick poc that works well: 0x6a77/terraform-provider-flux@c7227c0