Update VS Code shell integration script

[andyleejordan]

Updates our embedded copy with changes made upstream, see microsoft/vscode#170516.

Fixes PowerShell/vscode-powershell#4343.

[andyleejordan]

@SeeminglyScience @Tyriar I think the change we make from Console::Write to Write-Host -NoNewLine could be shipped upstream, and I'm wondering if we should change:

# Only send the command executed sequence when PSReadLine is loaded, if not shell integration should
# still work thanks to the command line sequence
if (Get-Module -Name PSReadLine) {
	$__VSCodeOriginalPSConsoleHostReadLine = $function:PSConsoleHostReadLine
...
}

to

if (Get-Module -Name PSReadLine -and $Host.Name -ne "Visual Studio Code Host") {
	$__VSCodeOriginalPSConsoleHostReadLine = $function:PSConsoleHostReadLine
...
}

then at least I won't have to change those two things when importing the script, and that gets us closer to somehow doing what I think is the "Right Thing" and getting either PSES or VS Code to load the upstream shell integration script even for PSES Extension Terminals.

[SeeminglyScience]

LGTM!