Resize handle on the editor form

[titanomachy]

The only option right now is to hide or show the editor form. I would prefer a resize handle on the form, so that I can enter queries while viewing the graphs.

There is an issue in the Code Mirror repository about a missing resize handle: codemirror/codemirror5#850

There is another repository linked at the end, that implements the resize handle: https://github.com/Sphinxxxx/cm-resize

[n-riesco]

Thank you so much for the links.

[xparq]

I've just described in a related CM issue a new implementation, which is the simplest yet, and does not need any JS drag-and-drop or custom drawing tricks, but relies on more straightforward and robust HTML5 features instead.

(Because of that, browsers, which don't support those (pretty standard) features yet, will just have no resize, as before, so no harm is done. And when they catch up, resize will just start working for them, too. Edge is one of those, BTW.)

[n-riesco]

@lunakid Thank you for the link!

I'm planning to address this issue when we replace react-codemirror with react-codemirror2 (issue #401).

[xparq]

Great!
(BTW, I removed from my comment above a confusing remark about issue merging, which got there by mistake. :) )