[resource] Multiple files add

[lgilies]

When the user Drag & drop multiple files, the uploading process expects to start for all files automatically and start to track the progress independently for each file.

See #1 for background.

Wireframe

Acceptance

• Be able to upload multiple files
• Be able to track the upload progress independently for each file
• Be able to edit metadata for each of the uploaded files
• Be able to hit save (and save everything) once all uploads complete
  • Send each resource independently and remove from the UI list, so the user can edit/save the others resources and in the last resource sent, will redirect the user to the dataset page.
• Be able to use the edit resource page

Tasks

• Render all files in the upload info area
  • create an array with all files
  • insert this array of files in the state
  • each file should be identified with a unique key
  • the unique key also should be pass when the user clicks in the card uploading, so I can do any action for that file.
• Use all the steps above for edit resource page

Questions:

• Do we need to limit the file size?
• Do we need to set the type of these files? ie. only accept CSV

[mariorodeghiero]

@rufuspollock I already can Upload multiple files, edit metadata, and edit schema, but there is a behavior we didn't talk about. When the user clicks in "Save and Publish" and we have a list of resources.

Behavior today: Send the resource and redirect the user to the dataset page

Options that think:

1. Send each resource independently and remove from the UI list, so the user can edit/save the others resources and in the last resource sent, will redirect the user to the dataset page.

2. If the user clicks in "save and publish" will iterable the array and send all the resources and after redirect the user to the dataset page. (maybe can be a problem for fields required like restricted)

[mariorodeghiero]

FIXED. In the future, we need to check how it works for the edit resource page.