Allow ICliActions in plugins to run isolated

Currently e.g. the tap package install command run in "isolated" mode (from a tmp folder). That this mode is used for this particular action is hardcoded. We should make it possible for other actions developed separatly from OpenTAP itself to also run in this mode.

The REST API package would need this to implement an tap image install command.

To run in this mode an ICliAction plugin would need to inherit from a new IsolatedPackageAction base class that itself inherits from LockingPackageAction. The DisplayAttribute name or group on the ICliAction plugin would also have to be "install" or "uninstall" for now.