[Feature Request] update hover messages

Context

• This issue is not a bug report. (please use a different template for reporting a bug)
• This issue is not a duplicate of an existing issue. (please use the search to find existing issues)

Description

Hello,

I'm using provideHover for the hover feature of my editor. As a result, when we hover on a text in the editor (or select a text then press Ctrl+K Ctrl+I), we see its hover message.

Previously, the content (let's say Content A) of the hover message was very fast to generate. Now, I would like to add more content (let's say Content B) on top of Content A. Content B requires several seconds to generate. So an expected scenario is that when people select a text then press Ctrl+K Ctrl+I, we see first Content A (and maybe Calculating Content B...), then several seconds later, we see Content A and Content B in the hover window.

Is it achievable in the current Monaco Editor?

Start by reviewing the provideHover API and the hover flow used when text is hovered or when Ctrl+K Ctrl+I is pressed. Determine whether the current API supports showing existing content before slower content is ready, and document the supported behavior or the design needed to achieve it.