Fixes #218626

[swordensen]

This is to resolve #218626

Basically, it prevents windows from popping up when dragging files over to extensions from the OS's file explorer.

You can test this functionality by performing the following steps:

1. clone repo https://github.com/maxbublik/vscode-customeditor-drop
2. press f5 to open demo repo as an extension
3. drag and drop any file into the extension editor while holding shift
4. notice that a new window did not appear

[swordensen]

I added a fix that addresses #219047

[swordensen]

Since #219896 got merged I will need to bring back the original changes on this PR before it gets merged.

I am going to change this to a draft status.

[edit] #219896 did not merge into master. That's really cool. I will undraft this

[mjbvz]

Thanks for following up! Will get this into the next insiders build which should go out at the start of next week

[swordensen]

Thanks for following up! Will get this into the next insiders build which should go out at the start of next week

no problem! and no rush on my end. I'm sorry for any headaches my last PR caused. It feels good to help fix it!

[swordensen]

I was thinking about this again today and I am a little concerned that if this fix PR is not merged before the July release we may encounter the same issue(s) with the June release.

Since, I don't think the reversion here #219896 would be included. I am not 100% sure about that though.

[mjbvz]

Thanks for following up! Let's try this again for the August release since we'll have more testing in insiders