Add Code Editor Panel Open/Close button

[AdRiley]

Add new button bottom left to toggle open/close of code editor

icon: bottom_panel

Closed

Open

Doc panel and code panel open

Notes:

• Screenshots for concept only. Sizing/spacing to be determined by implementor
• Add component button moves bottom right and moves in when code panel or doc panel opened
• Red cross for close should go
• Maybe left gutter could be wider
• Button up/down should match the doc panel up/down coloring
• Code editor is now fixed width across bottom of screen.
• When doc panel open. Code editor shrinks.
• Resize handle can go.
• Entire top edge should allow vertical resizing
• Entire top edge should have vertical resize cursor