Allow installation of unsigned plugins using an URL

[llluis]

Proposed Changes

Allow the installation of Grafana plugins directly from an URL and also add an option to allow running plugins which are not signed. This is a breaking change as plugin list now must have the key name on it to allow the URL key part of it.

Related Issues

None

[llluis]

All comments resolved. Let me know what do you think @frenck and thanks much!

[github-actions[bot]]

There hasn't been any activity on this pull request recently. This pull request has been automatically marked as stale because of that and will be closed if no further activity occurs within 7 days. Thank you for your contributions.

[llluis]

@frenck I completed all changes and would like your review so this can be merged. Can you please take a look? Please let me know if I'm missing something.

[tomlut]

Awesome! Thank you for this Luis.