mgr: Allow modules to get/set other module options

mgr: Allow modules to get/set other module options

Add the _ceph_get_module_option_ex and _ceph_set_module_option_ex methods to the BaseMgrModule. This allows a module to get/set options from other modules, e.g. allow the Dashboard to set the telemetry module settings, either the other module is not enabled.

Fixes: https://tracker.ceph.com/issues/37722
Signed-off-by: Volker Theile <vtheile@suse.com>