clean up foobazdmx role

make git repo url and version to check out a variable instead of a
hard-coded value the role, and update host_vars to match.

playbooks/roles/foobazdmx/meta/argument_specs.yaml

@@ -2,6 +2,14 @@
 argument_specs:
   main:
     options:
+      foobazdmx_version:
+        description: git branch, tag, or commit to check out from the foobazdmx repo
+        type: str
+        default: main
+      foobazdmx_repo_url:
+        description: git repo to pull foobazdmx from
+        type: str
+        required: true
       foobazdmx__art_net_host:
         description: IP oder hostname of the Art-Net server
         type: str