Final graphics clean up

[SamuelHo10]

• Test the full place and route flow, the analysis only flow etc. with graphics and make sure the status bar messages come out at the right time (should say "placement complete, estimated critical path is xx" and then "routing succeeded with a channel width of yy" etc.). When you demoed the graphics, the routing success message instead showed up after you hit next step, just before the program exited.

• Test that the critical path display works, both with flylines and with routed nets. Move the critical path display options under nets and make them similar (checkbox for delays, drop down for flyline vs. routed & a toggle for critical path shown or not) to the existing net controls. Use a vertical separator to divide them from other net controls. Probably the flyline vs. routed option can just be tied to the existing net option / dropdown for that -- that might be less cluttered and less confusing.

Previously, we had options to show flylines and routing for critical path at the same time which I think might be a useful feature to keep, so I used checkboxes for the flylines/routing.

• Add a status bar message when you choose select zoom that tells you what to do (left click on the two diagonally opposite corners of the desired zoom)

• Update the documentation to describe all the various graphics options

I only had the time to update the documentation for the Nets and Routing Resource section.

Other minor changes include fixing the highlight functionality when multiple nodes are selected using ctrl + click, and ensuring that the intra-cluster flyline nets option is available even when flat routing is off.

[AlexandreSinger]

LGTM. Just one typo.

[AlexandreSinger]

whill -> will

[vaughnbetz]

Thanks a lot @SamuelHo10 ! Lots of nice fixes here. Merging this, and we can fix the typo @AlexandreSinger found in a separate PR.

[AlexandreSinger]

Thanks a lot @SamuelHo10 ! Lots of nice fixes here. Merging this, and we can fix the typo @AlexandreSinger found in a separate PR.

Done: #3253
Have a great rest of your summer @SamuelHo10 , thanks for all your help!