Add encodeFormBody utility and form data content type support

[mtuchi]

Summary

This pr add form data encoding support across the adaptors by adding a shared encodeFormBody utility to @openfn/language-common and use it into @openfn/language-dagu and @openfn/language-http.

Details

@openfn/language-common

• Added encodeFormBody(data) to src/util/http.js — encodes a plain object into a FormData instance
• Added unit tests for encodeFormBody including edge cases (null/undefined skip, Blob passthrough)

@openfn/language-dagu

• Added contentType support to RequestOptions, enabling requests to be sent as multipart/form-data using encodeFormBody under the hood

@openfn/language-http

• Use the shared encodeFormBody utility from@openfn/language-common for form data encoding.

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• Does the PR do what it claims to do?
• If this is a new adaptor, added the adaptor on marketing website ?
• If this PR includes breaking changes, do we need to update any jobs in
  production? Is it safe to release?
• Are there any unit tests?
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  dev only changes don't need a changeset.
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[mtuchi]

@PiusKariuki this should fix your problem, You will need to pass contentType: 'form' as your request option

post(
  `/Patient/Prescription/History`,
  {
    start: 0,
    length: -1,
    draw: 1,
    additionalParameters: {
      filter: [
        { fieldName: 'prescriberName', operator: 'Eq', value: 'Dr Super User' },
      ],
    },
  },
  {
    contentType: 'form',
  },
)

[mtuchi]

SurveyCTO have it's own version of encodeFormBody, Technically the new version of encodeFormBody from common should replace this function, but there are not enough unit test or integration test to do the swap. will discuss with joe next steps for surveyCTO if the pr is approved

[josephjclark]

The blob stuff makes me nervous. I can see how we're trying to make it easy to encode form data but I don't actually think it's working 🤔

Let's make the form encoding super simple. Just pass blobs through. You'll probably need to stringify objects, otherwise just ensure strings

To enable files and binaries we need a helper function like createBlob(data, type, filename). This will have to return some kind of wrapped object (maybe a class instance) which the encoder knows how to handle

[mtuchi]

Hiya @josephjclark , i have removed the blob stuff and open a ticket for adding createBlob in common/util

[mtuchi]

Hiya @josephjclark , i have removed the mode option from encodeFormBody. Now you can just use encodeFormBody(data). But i am still supporting Blob and File which will be appended as-is.

The idea is, User should still be able to pass a Blob or File as-is

const blob = new Blob([ArrayBuffer], { type: "image/png" )
encodeFormBody({blob})

what do you think of this approach ?