"Resize all columns" option in context menu on column headers

[rbasralian]

It would be great to add a "resize all columns" feature (like the swing UI has) to automatically resize columns to fit their data/headers. It's really useful for keeping the UI compact.

For example, in the table below my columns all got way too wide, and it would take forever to make them compact again (I'd have to keep scrolling right just to grab the column separator to drag it):

Just for context, this is the button I'm talking about:

Relates to #885

[vbabich]

We have automatic column resize on separator double-click, like in Excel. Don't have a "resize all columns" feature, though.

[mofojed]

Would also be nice to have the "Auto Resize" option available available on a column as well, to disable auto resizing on a particular column (or the whole table?)