Add file upload component

[larowlan]

Feature Request

• [x] I’ve read and understood the Contributing guidelines and have done my best effort to follow them.
• [x] I’ve read and agree to the Code of Conduct.
• [x] I’ve searched for any related issues and avoided creating a duplicate issue.
• [x] I've searched the community forums to check for related issues or feature requests

Do you have a suggestion for a new component?

File upload form control. Couldn't find an existing issue. Support for multiple files. Possible progress bar.

Other request?

Additional context

UK reference: https://design-system.service.gov.uk/components/file-upload/

There is a discussion about this in the forum- https://community.digital.gov.au/t/file-uploads/912

[sukhrajghuman]

@larowlan would be great to have this as a component, thanks for bringing it up!