Clear/re-fetch forms after project is encrypted

Steps to reproduce:

1. Navigate to the project overview for a project that has a form and is not encrypted. The form's version string is indicated.
2. Navigate to project settings and enable encryption. This will create a new version of the form.
3. Navigate back to the project overview. The old version string is indicated for the form, not the new one with the `[encrypted:...]` suffix.

After encryption is enabled, the `project` is cleared and re-fetched. I think we should also clear `forms`. That way, if the user navigates from the project settings to a route that requires `forms`, those will be re-fetched with the new version strings.