lang: Replace the go-bindata usage with embed

This doesn't let us have nested mcl at the moment, but we could improve
on this with an embed API for each package. For now this makes building
the project easier.

.github/workflows/test.yaml

@@ -37,9 +37,8 @@ jobs:
       #fail-fast: false
 
     steps:
-      # Do not shallow fetch, will fail when building bindata/
-      # The path can't be absolute, so we need to move it to the
-      # expected location later.
+      # Do not shallow fetch. The path can't be absolute, so we need to move it
+      # to the expected location later.
       - name: Clone mgmt
         uses: actions/checkout@v2
         with: