Actionabilize errors from incorrect settings files

[travisclagrone]

Fixes #1053 "Errors from incorrect settings files are not actionable".

[travisclagrone]

The first commit adds only research comments, and the last commit reverts them. However, I have chosen to leave the commits in for documentary purposes in the history. In particular, I imagine that further work either refactoring or extending this code region might benefit from them.

[bergmeister]

First of all thanks for making the effort and improvement. I agree that throwing a terminating error here is the right decision. One minor comment but hold off from addressing it at the moment, I will add more reviewers so that they can decide as well. But otherwise, it looks good to me. In the future we might enhance it to emit DiagnosticRecords of type ParserError in lower levels so that people get highlighting in VS Code but your change to improve the command line experience is good as a first improvement.
The red Ubuntu build can be ignored for the moment, this is a problem with the recent image update in AppVeyor that is also affecting the main development branch.
With the recently merged PR #1250, which improves the exceptions that are reported, this gives us now nice messages like this @JamesWTruher :-)

Invoke-ScriptAnalyzer -ScriptDefinition gci  -Settings @{foo='bar'}
Invoke-ScriptAnalyzer : foo is not a valid key in the settings hashtable. Valid keys are ExcludeRules, IncludeRules and Severity.
At line:1 char:2
+  Invoke-ScriptAnalyzer -ScriptDefinition gci  -Settings @{foo='bar'}
+  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : InvalidData: (System.Collections.Hashtable:Hashtable) [Invoke-ScriptAnalyzer], InvalidDataException
+ FullyQualifiedErrorId : InvalidSettingsData,Microsoft.Windows.PowerShell.ScriptAnalyzer.Commands.InvokeScriptAnalyzerCommand

[rjmholt]

I think @JamesWTruher was working on something in this space as well.

Ideally this should actually throw an AggregateException and tell you all of the configuration problems (that's the general pattern for a parser, so you can fix as much as possible).

But I think this is a step in the right direction.

[rjmholt]

@bergmeister agreed re integration for other contexts; ideally rather than a parse error the error should be something PSES can catch and then display as a notification. We should discuss what the best design is there, especially in terms of revising the hosting model (@JamesWTruher)

[bergmeister]

Thanks, looks good to me, just one minor cleanup nit

[bergmeister]

Nit: With the last commit, this using statement is not needed any more.

[travisclagrone]

using System.IO; does appear to be required for pre-existing unqualified references to the type System.IO.InvalidDataException.

[bergmeister]

Not any more after the last commit that removed this type. I pushed a last commit to fix this and do some minor cleanup and make the format consistent to the solution and merge then after this.