Add rake geo:db:foreign_tables_out_of_date

What does this MR do?

This task is intended to be called by omnibus during reconfigure to determine if rake geo:db:refresh_foreign_tables should be run.

It is option 2 of omnibus-gitlab#4672 (comment 218542272):

1. tell omnibus to run the check, and parse it to know if we need refresh
2. or add a rake task that returns 1 if need refresh
3. or guard rake geo:db:refresh_foreign_tables with the check, and always run the task on reconfigure

Although I did the inverse: rake geo:db:foreign_tables_out_of_date returns 0 if refresh is needed. It returns non-zero if not needed (or if any other error happens). This will avoid running the refresh task when errors are happening.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Part of omnibus-gitlab#4672 (closed)