Bring your own ReadLine

[dkattan]

The Problem

I am unable to create a web based script editor with a terminal because both PSReadline and LegacyReadLine ultimately call Console.GetKey and Console.Write, causing the input and output to be mapped to the calling process’s Console.

Suggested Fix

Add a -UseUnderlyingHostReadline switch and change the following code:

** https://github.com/PowerShell/PowerShellEditorServices/blob/bd34695f31eebe8eaea5523a13a754da548153f5/src/PowerShellEditorServices/Services/PowerShell/Host/EditorServicesConsolePSHostUserInterface.cs#L86**

To call _underlyingHostUI.ReadLine() if -UseUnderlyingHostReadline is specified

[andyleejordan]

Linking PR https://github.com/PowerShell/PowerShellEditorServices/pull/1748