Add Developer Mode to Issie

[timothycdc]

Features:

• Shows mouse position and the id of hovered component/wire.
• Select a symbol to view its component info, ports, and port maps.
• Select a wire to view its properties and segments.
• The box created on when clicking and dragging (dragToSelectBox) also contains sizing information to be used as a ruler.
• Scroll position of the developer mode persists in between updates.
• Shows other useful sheet heuristics such as the number of bends, visible segment lengths, etc. The developer has an option to 'hold' values statically for comparison. More explanation is provided on hover via tooltips.

Dev mode only appears when debugLevel > 0, when npm run dev is called. Otherwise it does not show up in the final build.