Blender Git Loki

Fix potential early-return in WM foreach_id process.

Add a function to check if iteration over ID usages should stop (using
internal `IDWALK_STOP` status flag).

Use it in `BKE_LIB_FOREACHID_PROCESS_` macros, and in
`window_manager_foreach_id` to handle properly the active workspace case
(previous code could skip the call to `BKE_workspace_active_set` in case
iteration over ID usages was stopped by callback on that specific ID
usage).

Part of T90922: Fix return policy inconsistency in `scene_foreach_id`.