Cleanup bags button freezes inventory

Description:
When you go into your backpack and click on "Cleanup bags" button (top-right corner of the bag UI) your items freezes (their icons turn gray). In order to unfreeze them you have to relog.

Current behaviour: Clicking on "Cleanup bags" button (top-right corner of the bag UI) your items freezes (their icons turn gray)

Expected behaviour: Items in the bag should be sorted or "cleaned up" like in retail or at the very least the button should not freeze your items and do nothing instead (until cleanup feature is implemented).

Steps to reproduce the problem:

1. Open your character's backpack
2. Click on "Cleanup bags" button at top-right corner of bag UI.

Branch(es): 6.x

TC hash/commit: 22d29ce0494c32a73e20646d2320a44a5eb2e633

TDB version: 6.04

Operating system: Windows 10 64bit

P.S. While it is quite a minor issue, my suggestion would be to disable button all-together (user presses it and nothing happens) until its functionality is implemented.

Reproduce the issue on the 6.x branch at commit 22d29ce0494c32a73e20646d2320a44a5eb2e633 by opening the backpack and clicking the top-right "Cleanup bags" button. Trace the backpack UI entry point and verify that cleanup either sorts the items or leaves them usable without freezing; if cleanup is not implemented, the button should safely do nothing.