Add WS api/editions/uninstall

WS api/editions/uninstall uninstalls the current SonarSource edition.

Requires System administer permissions
No param

Fails if:

• install of an edition is in progress (or in error)
• There is no edition installed

The uninstallation of plugins should be done synchronously.
The license should be removed while stopping the server.
The removal of the plugins and the transition to the final uninstalled state will be effective at startup.