For replicables in the Geo self-service framework, by default, this:

- hides primary checksum progress bars
- stops the primary from enqueuing checksum jobs for new records

The above is appropriate and should have been the case before, because
verification is still under development.

Package file verification gets its own feature flag so we can release it
first by itself. Package file verification can be enabled by running in
Rails console:

- `Feature.enabled?(:geo_package_file_verification)`

Verification of non-package files (MR diffs, Terraform states, Snippet
repositories) can be enabled with:

- `Feature.enabled?(:geo_framework_verification)`