Support more richtext format when copy-and-paste, like google docs and slack

[Stupidism]

Background

Our editor found bold and italic information missing when paste into payload from google docs.
So I had a deeper dig found the richtext format from some platforms are not supported:

• asana
• contentful
• google docs
• slack

From google docs

From slack

Only italic is copied

[EasonSoong]

Paste link from contentful couldn't work either.

[EasonSoong]

I notice if data.types.includes('application/x-slate-fragment' , the code won't handle the pasted data deserialize, and pass the data to editor.insertData will causes this issue.