Add ability to update power level/grant admin in top level bridged spaces

[PoodlePalace]

When bridging my discord to my Cinny homeserver, similar to this issue I had some rooms that didn't make it to the spaces they originated from. After some time the system seemed to actuate properly and put them in their appropriate spaces, but it unsorted them from the original order they were in.

Presently there is no way to sort rooms since the mautrix-discord bot is the only one with permissions to do so. I tried using the set-pl command, but it only works in rooms, not spaces, so I am still unable to move things around or change permissions. AFACT there is no way to increase your permissions at the space level, the only other bug I can find mentioning it here, so I am submitting a feature request to allow modification of power levels at the space level to grant specified users Moderator or Admin permissions.

This would not only allow room sorting, but allow users to have more control in general over their discord bridges in their own servers.

[alterNERDtive]

I tried using the set-pl command, but it only works in rooms, not spaces, so I am still unable to move things around or change permissions.

Funnily enough it works in sub-spaces (created from categories in a Discord guild).

Would be great to see this in the spaces created for guilds as well.