Upload multiple images through react-mde

[srosset81]

Example in https://codesandbox.io/p/sandbox/react-typescript-icqgv?file=%2Fsrc%2Findex.tsx

We only need to add this prop:

<MarkdownInput source="pair:description" fullWidth reactMdeProps={{ paste: { saveImage: save } }} />

With the save function looking like this:

const save = async function*(data, file) {
    // Upload "data" to your server
    // Use XMLHttpRequest.send to send a FormData object containing
    // "data"
    // Check this question: https://stackoverflow.com/questions/18055422/how-to-receive-php-image-data-over-copy-n-paste-javascript-with-xmlhttprequest

    // yields the URL that should be inserted in the markdown
    yield "https://picsum.photos/300";

    // returns true meaning that the save was successful
    return true;
  };

The data param is an ArrayBuffer, while file seems to be a regular File.

To make it work, we would only need to move the uploadFile util to the data provider interface.

Estimate time: half a day