Add option to throw on failure

[nohwnd]

Throw on failure when enabled. If you want to process the result for some reason after catching the exception, you need to use

$result = try { Invoke-Pester ... } catch { $err = $_ }

And not

try { $result = Invoke-Pester ... } catch { }

Because then the assignment will never happen and $result will be null.

But in such case it is better to just not enable the throwing and throw yourself based on the .Result

Fix #1843

[nohwnd]

@JustinGrote I think you also asked for this somewhere.