core (memory/params): added `extra` argument to filter out params notably in `getParamsUI`: In some case, it may be desirable for a frontend to not expose some parameters to user (e.g. it is the case on Android with the `autoconnect_backend` parameter). An new `extra` parameter has been added to a couple of parameters method for that: it can contain the `ignore` key with a list of [category, name] of parameters to skip.