ItemButton:With Loading

Build 3906 on claude/button-item-current-theme-js20o6
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Baseline History
Build 3906f37a0d0
Current build. There are unaccepted changes, so build 3841 is still the baseline.
Build 384128deeac current baseline
Accepted by Andrey Yamanov.
Build 34389e249f2
Accepted by Andrey Yamanov.
Build 3403653dc73
Accepted by Andrey Yamanov.
Build 3401252313d
Accepted by Andrey Yamanov.
Commenting is disabled because there's a newer build on this branch