From-To-Picker is being imported incorrectly into StopsOverlay

[PaulIvanov]

When attempting to use the StopsOverlay package inside of the new trimet.org site, we ran into a webpack build error, that we believe is a symptom of a bigger issue:

ERROR #98123  WEBPACK
Generating development JavaScript bundle failed
Unexpected token (11:14)
File: node_modules\@opentripplanner\from-to-location-picker\src\index.js:11:14

The contents of that file (and otp-ui in general) look to be utilizing "@babel/plugin-proposal-class-properties": "^7.7.4",. The class properties in FromToLocationPicker havent been transpiled into valid JS within the library, so our webpack build fails.

After digging deeper into this, to find a solution, we believe the offending line of code is within packages that contain a module:

 "main": "lib/index.js",
  "module": "src/index.js",

We found an SO issue discussing the module item makes es6 module imports to use the specified file instead of the minified lib code: https://stackoverflow.com/a/47537198/4625508. We arent fully sure if this is the cause/root of the webpack issue, But we think its a solid starting point for continuing to investigate the underlying issue.

[PaulIvanov]

@fpurcell this is a blocking issue that prevents us from implementing the StopsOverlay in the Trimet.org site