Selecting patterns in feed viewer patterns or stops tab results in blank screen

[binh-dam-ibigroup]

Observed behavior (please include a screenshot if possible)

Selecting a route or a pattern in the Patterns or Stops tab in the feed version viewer results in a UI crash. This is probably related to leaflet. Error message in the console:

leaflet-src.js:1656 Uncaught TypeError: Cannot read properties of undefined (reading 'lat')
    at Object.project (leaflet-src.js:1656:1)
    at Object.latLngToPoint (leaflet-src.js:1493:1)
    at NewClass.project (leaflet-src.js:3956:1)
    at NewClass.latLngToLayerPoint (leaflet-src.js:3978:1)
    at NewClass._getCenterOffset (leaflet-src.js:4481:1)
    at NewClass._tryAnimatedPan (leaflet-src.js:4556:1)
    at NewClass.setView (leaflet-src.js:3159:1)
    at Map.updateLeafletElement (Map.js:131:1)
    at Map.componentDidUpdate (Map.js:261:1)
    at commitLifeCycles (react-dom.development.js:20684:1)
...
react_devtools_backend.js:4026 The above error occurred in the <Map> component:
    at Map (http://localhost:9966/dist/index.js:262310:25)
    at GtfsMap (http://localhost:9966/dist/index.js:30727:5)
    at Connect (http://localhost:9966/dist/index.js:268818:28)

Expected behavior

There should not be a crash.

Steps to reproduce the problem

1. Open a feed version
2. Select the Patterns or Stops tab
3. Select a route and/or a pattern
4. Observe that the screen blanks out.

Any special notes on configuration used

NA

Version of datatools-ui and datatools-server if applicable (exact commit hash or branch name)

Datatools-server dev branch, datatools-ui version that includes #750.