Webpack 5 error

[twelch]

Upgrading dependencies to webpack 5, as attempted in this PR, causes a runtime error in React with "Context not set" after giving the message to run the area function.

Reproduce:

• Create a new project with gp-area template
• Run start:client and point at any published gp lambda = https://localhost:8080?service=https://qqpj5fzzoj.execute-api.us-west-1.amazonaws.com/prod/. Should be able to point at any published GP lambda with an area function with Area client.

Storybook still being on webpack 4 doesn't appear to be the issue but that is the case. Until we have a pressing need to upgrade to webpack 5 we may want to wait for this to resolve - storybookjs/storybook#9216

[twelch]

I did a bisecting process to determine the last good commit that the Client would run a function and display the results properly was 02a03a6.

I created a branch off of dev at the next breaking commit a5d5ab - https://github.com/seasketch/geoprocessing/tree/a5-fun. Then, I rolled back the dependency upgrades and then with a run start:client I was able to successfully load an Area client. Bumping the versions again, I could reproduce the context not set error.

window.postMessage({
    "type": "SeaSketchReportingMessageEventType",
    "client": "Area",
    "geometryUri": "https://www.seasketch.org/geojson/607f3953a967192577003534",
    "sketchProperties": {
        "id": "607f3953a967192577003534",
        "name": "Test Example Project",
        "createdAt": "2021-04-20T20:28:03.607Z",
        "updatedAt": "2021-04-20T20:28:03.607Z",
        "sketchClassId": "5edfa3a8a1a9956b48ece131",
        "isCollection": false,
        "userAttributes": [],
        "visibleLayers": []
    }
})

[twelch]

Once webpack 5 comes, these other dependencies left behind can be upgraded - #27

[twelch]

storybook is stuck on webpack 4 for now, it probably won't change until its next breaking major release (v7) where it may support multiple transpilers. anyway storybook can probably be isolated ot use v4 while the rest of the stack uses webpack 5 if that's useful.