Add Table Column context menu item to reset to designed size.

[lailoken]

Version/Branch of Dear ImGui:

imgui branch: docking, version: 1.93.0 WIP (19292)

Back-ends:

(Multiple)

Compiler, OS:

(Multiple)

Full config/build information:

N/A

Details:

We already have the ability to reset tables columns to designed order and visibility, can we add the ability to reset to column widths as well? (if applicable/appropriate)

Screenshots/Video:

Minimal, Complete and Verifiable Example code:

[ocornut]

Will work on this at some point. It's not as trivial as you'd imagine because there's a confusion with the "Size all columns to default" option that appears when ColumnsEnabledFixedCount != ColumnsEnabledCount which would then become misnamed.
The equivalent size all path for Stretch columns is different than for Fixed columns and that needs some clearing up to find the right unambiguous wording for varying sizing policies combinations.