Add insertFromComposition and deleteByComposition inputTypes

[ZhangYiJiang]

Summary

Add Input Events Level 2 insertFromComposition and deleteByComposition inputType events

Test results and supporting details

For each browser, on macOS pinyin IME input a 1 (inserting 啊), then selecting the inserted text and input b 1 (deleting 啊 and replacing it with 不). According to https://w3c.github.io/input-events/#event-order-during-ime-composition we should see

• deleteByComposition beforeInput and input events for the second test since 啊 is being deleted
• insertFromComposition beforeInput and input events for both cases

Firefox: https://input-inspector.vercel.app/profiles/8n74DRvc3g5dhl6pMYQo - neither event fires
Chrome: https://input-inspector.vercel.app/profiles/AXWWGKNTootDNMo6pXcY - neither event fires
Safari: https://input-inspector.vercel.app/profiles/Hocw2xtbGkIbqgFwXzQP - insertFromComposition fires but deleteByComposition does not. I don't know when this was added, so this is just left as true

Firefox - the original bug for supporting inputEvent notes both these level 2 events will not be implemented yet https://bugzilla.mozilla.org/show_bug.cgi?id=1447239

Related issues

[queengooborg]

Thank you for your PR, and welcome to BCD! Currently, we are in the process of deciding whether or not to allow all-false entries in BCD -- see #10619 for more details. I will be marking this as "not ready" accordingly.

[queengooborg]

Hey again @ZhangYiJiang, thank you for your patience on this! We have decided not to include features that have no compatibility in BCD. A spec may implement a feature, but then rename or remove it before any browsers implement it, thus leaving a leftover statement in BCD.

Would you be down to research if any browsers support this feature now? If not, I'd be happy to look into it and follow up!

[queengooborg]

I'm going to close this now since it's been over two months and there has been no response and I'm seeing no signals that any browser supports these. Thank you anyways!