Update Private Plugins Page For Dev Versions

[dericksozo]

• Existing private plugins will have a button to add this version. New private plugins will have this version OOTB
• This PP (private plugin) version will not require a tag in github and will be "live" and taken from the latest repo / branch.
• It should be used while developing the PP (so no need to create a version and publish it every time a user wants to test the plugin)
• This version won't be the "latest" for services / templates which are using this option for this private plugin