feat: add option to allow dropping a directory and reading the contents

[gvdp]

This is an attempt at resolving #2 , to support dropping folders.

We needed this for one of our clients, so I tried to add the option. It's a bit convoluted but the whole File and Directories web API is not so easy to use. Definitely open for ideas (and suggestions for better testing / documentation), but it would be great if we could add this to the package, for now we're publishing and using a forked version which works but is not ideal.

It also does use the non-standard webkitGetAsEntry file api but as said in this comment it is widely supported:
#2 (comment)
https://caniuse.com/?search=webkitGetAsEntry

[gilest]

Thanks for this contribution. I'll try to review later this week

[bertdeblock]

Hey @gilest, would you be willing to review, if we update this PR?

[gilest]

Hey @gilest, would you be willing to review, if we update this PR?

Yes I'm open to reviewing it. From memory it looked ok but there's a bit of async-waterfall happening, probably unavoidable.

Was curious about how in-demand this feature might be but it seems reasonable to include.

We also have better tests and tooling now to experiment with a feature like this before merging.

[gvdp]

I'll close this one since I recreated it based on the latest master changes so there are no more merge conflicts:
#1066