Add a second view with signature information

[mjbvz]

Request

Add another view called Signature Info that shows the signature help (parameter hints) information at the current cursor position.

From: microsoft/vscode#51253

[sandipchitale]

@mjbvz What is precisely meant by parameter info? Does Documentation view already shows that info? If I understand clearly what is different about Signature information which is not already covered by Documentation, I could submit an (almost ready) PR.

BTW if Signature Info is not part of Hover, is there an API to get it in extension code? Actually figured it out:

private getSignatureHelpAtCurrentPositionInEditor(editor: vscode.TextEditor) {
		return vscode.commands.executeCommand<vscode.SignatureHelp[]>(
			'vscode.executeSignatureHelpProvider',
			editor.document.uri,
			editor.selection.active);
}

[mjbvz]

@sandipchitale Yep, the signature help is what I meant. Looks like you already found the right api to use for it too! Let me know if you run into any issues working on this

[sandipchitale]

Feel free to adjust the formatting. Note that it shows a green square next to the active (current) signature. Shows a black square next to the inactive signature.