For acceptance/bundle/templates I'd like to run "bundle deploy". This
would create .databricks directory inside materialized output. It might
makes sense to commit some of this as part of golden files output. Even
if we did not commit anything, the test runner will see those files and
show the difference. Thus git should also see them.
Also rename .gitignore to out.gitignore in those tests, since that
includes .databricks as well.
## Changes
Include a materialized copy of built-in templates as reference output.
This updates the output comparison logic to work against an output
directory. The `doComparison` function now always works on real files.
It can now tell apart non-existing files and empty files (e.g., the
`.gitkeep` files in templates).