feat: support inlay hints

[johnsoncodehk]

LSP Issue: microsoft/language-server-protocol#956
Document: https://code.visualstudio.com/updates/v1_60#_inlay-hints-for-javascript-and-typescript

This feature still in VSCode Proposed API, LSP don't support yet, currently implement by VSCode client API, and only able to test in VSCode Insider.

Setup:

1. Launch VSCode Insider (1.60 later) by command code-insiders . --enable-proposed-api johnsoncodehk.volar.
2. Install volar-0.27.13-inlay-hints.2.vsix.zip to VSCode Insider. (You can bulit it youself by npm run pack command)
3. Search inlayHints in VSCode settings and enable features your needs.

Reference: https://code.visualstudio.com/api/advanced-topics/using-proposed-api#sharing-extensions-using-the-proposed-api

[Kingwl]

Looks good.

[oxk4r01]

Ok, done. But there are some issues:
When the editor is splitted vertically or horizontally hints dissapear,
Same if I update the extension to v0.28.

[johnsoncodehk]

@oxk4r01 This PR is implement in 0.27.13, how do you update to 0.28?

[oxk4r01]

VSCode downloaded automatically v0.28. I had to disable auto updating for the extension.

[johnsoncodehk]

@oxk4r01 This feature is not available in the automatically updated version, because vscode does not allow release experimental features, please wait for this feature to leave experimental on vscode.

[oxk4r01]

Then maybe it changed the version due to the sync settings config. I have v0.28 in another computer. I don't know.

[Shinigami92]

Would you like to give this a new try? 😃

[johnsoncodehk]

Would you like to give this a new try? 😃

Can't implement yet, still have to wait to out of proposed in vscode.