personal room names / room nicknames

[homchom]

Describe the problem

I can't change a room name without changing it for everyone; this is most problematic in direct messages, where I would like to assign a nickname to a friend.

Describe the solution you'd like

Some form of personal room names / room nicknames in the Cinny client, which are client-side and do not affect anyone else.

Alternatives considered

none

Additional context

Direct messaging tools often have a feature like this, for example friend nicknames for Discord and Steam.

[ajbura]

you can change your nickname in any room with /myroomnick command followed by your nickname.

[notramo]

@ajbura, I guess @homchom wants to change a displayname of an user only locally. iamb has this feature: https://iamb.chat/configure.html#user-display

Since the Matrix protocol does not have a spec for this yet, what about using localStorage for this?