Background

registry pull <provider> <version> ; simply adds the specified version of the provider and does not change anything if the version is older than one already downloaded.

Acceptance Criteria

This piece of work is simply to that the effect of registry pull <provider> <version> ; is that the specified provider version is in use after the command is run.

There are likely two significant considerartions in implementing this:

1. Remove or otherwise hereafter ignore the more recent provider.
2. wipe any provder cache or pages such that the next call to the provider dereferences the desired version.

The detail of implementation should be thoroughly tested and explained in the PR comment.