Make drag:stop cancellable

[hnrq]

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This PR implements...

Makes drag:stop cancellable. Once cancelled, originalSource returns to its initial position. The item won't be moved. Also, replace HTMLNode.parentNode.removeChild(HTMLNode) with HTMLNode.remove().

This PR closes the following issues...

Addresses #524

Does this PR require the Docs to be updated?

Yes

Does this PR require new tests?

No

This branch been tested on... (click all that apply / add new items)

Browsers:

• Chrome 102.0.5005.115
• Firefox 102.0.5005.115
• Safari 15.4 (17613.1.17.1.13)
• IE / Edge version
• iOS Browser version
• Android Browser 11 (org.lineageos.jelly)

[tsov]

FYI: HTMLElement.remove() may not work on older browsers, but then again, maybe it's time to move on from IE11 lol