Update Plan wizard are step to use OpenLayers

[maurizi]

Overview

Update Plan wizard are step to use OpenLayers. This will enable us to visualize layers Google Maps is unable to support, most notably vector tile layers.

Demo

Notes

• I rebased our ngx-openlayers fork on the latest upstream, to bring in support for OL 6
• OL provides easy access to a draw start event, so I was able to fix Add an undo or cancel button to "draw an area" #1301 fairly easily.

Testing Instructions

• scripts/update
• The plan page should continue to function as before, but with a new Google-free basemap
• The map page and map modal should continue to function as before

• [ ] Is the CHANGELOG.md updated with any relevant additions, changes, fixes or removals following the format of keepachangelog?

Closes #1335
Closes #1301

[flibbertigibbet]

The new maps looks nice, and interact well!

I noticed a few things in testing this:

• toggling to the plan 'Draw Area' tab only displays the map the first time; on subsequent toggles it's blank
• clicking the 'redraw' button while drawing causes the button to disappear until page refresh, and doesn't remove the shape in progress
• Loading the dashboard page for an organization with related map data for at least one related impact results in console errors:
  
• console error on opening map modal:
  
• the scroll size is off in the map modal, cutting off the bottom of the sidebar text:
  

Probably unrelated to this PR, but going to the plan page with an area already set for the organization doesn't zoom to fit the existing polygon.

[flibbertigibbet]

🎊

[maurizi]

@flibbertigibbet I think I've addressed all the issues you found.

Probably unrelated to this PR, but going to the plan page with an area already set for the organization doesn't zoom to fit the existing polygon.

This one is unrelated/intentional - I noticed this too, but it is only possible for this to happen if you reload the page while going through the Plan wizard, which seems likely to be uncommon, so I didn't think it was worth our time to address it.

[flibbertigibbet]

This is looking better! The console errors are gone. A couple of notes:

• on toggling between draw and autocomplete tabs in the plan wizard with a polygon already set, the map now always displays, but the polygon only shows the first time the draw tab is visited
• the map modal is looking better, but still can get cut off when in a short screen:

[maurizi]

@flibbertigibbet I've fixed the issue with bounds disappearing when switching tabs.

I was able to reproduce the issue with the map modal styling - I'd like to defer fixing that for now and see if #1342 fixes it, or tackle it in a later styling pass.

[flibbertigibbet]

👍