Issues when resizing side panel

[luabud]

Testing #133919

I placed the output on the side panel, and once I resized it I noticed a "..." with an additional views option, even though only output is displayed there so no other view options are available. Also if you look at the GIF, once you resize it by dragging the line towards the right, the items on the right side of the menu disappear from the window, it doesn't seem there's a "boundary" defined.

[sbatten]

this bug would affect all composite bars along with a few other bugs I discovered while fixing. I made some improvements to the overall calculation that should squash them all and hopefully not introduce new ones. If you are verifying, this change will allow the active tab to be hidden into the overflow menu if the width is super small

[rzhao271]

Going through the original steps, there's still a point after which dragging to the right results in the three icons to the right of the dropdown hiding from the sidebar.

[sbatten]

@rzhao271 what you observed is expected when the number of action icons in the toolbar and the overflow icon are still too much for the minimum width because we don't have any overflow logic for the panel actions. i will leave this as verified as we have a separate issue for that.