missing room_type in /_synapse/admin/v1/rooms/ API endpoint

[airblag]

I'm writting synapse admin tool to manage my homeserver. I wanted to add a subcommand for managing spaces, but as far as I searched, I cannot find any endpoint giving me a list of local rooms with room_type == m.space or any direct endpoint for dealing with spaces.

The endpoint /_synapse/admin/v1/rooms/ that I use to retrieve a room list is not returning room_type in the json.

It would be really helpfull to get it, to be able to identify spaces on a local home server.
Since spaces are just special rooms, I think it this way would be good enough to allow administrative interaction with spaces.

[clokep]

I think this is essentially a duplicate of #11904.