Set default role mapping filter in the role mapping modal

[Jamstah]

Description

We'd like to be able to set the default filter for the role mapping modal somehow so that client roles can be displayed to our users first.

Discussion

No response

Motivation

We only use client roles in our installations, so defaulting to showing the realm roles when adding a role to a user or group gives a jarring UX experience. We have many users who miss the filter altogether and don't manage to perform the action without digging into the documentation.

Details

Potentially, this could be done entirely with custom javascript in the theme, but I couldn't see a good way to do it without needing to know the exact version of the server.

[Jamstah]

@edewit can we consider this one for backport to 24?

Our customers are struggling with this one today, using 22, and the next release they will get to use is 26 (because we're on the RHBK schedule).

If there's another place I should be asking lmk :)