Strengthen ability to drive analysis via XML config files.

[michaelcfanning]

• BRK: All AnalyzeOptionsBase bool arguments are now bool? (to allow override in configuration XML. #2643
• BRK: SarifLogger no longer populates artifact data if locations only contain URI data. #2643
• BRK: Rename RuntimeConditions.ExceptionCreatingLogFile to `RuntimeConditions.ExceptionCreatingOutputFile. #2643
• BRK: Rename Errors.LogExceptionCreatingLogFile to Errors.LogExceptionCreatingOutputFile to reflect its general purpose. #2643
• NEW: Add DefaultTraces.ResultsSummary property that drives naive results summary in console logger via ResultsSummaryLogger. #2643
• NEW: Prove AnalyzeContextBase.Inline helper. #2643
• BUG: Raise ArgumentNullException on passing null text argument to HashUtilities.ComputeHashesForText. #2643