PR Summary

Update prediction interface to provide additional feedback to a predictor plugin.
The changes are:

1. Introduce PredictionClient to represent a client. It provides additional information about the type of the client: terminal, editor.
2. Update ICommandPredictor interface to replace the properties SupportEarlyProcessing and AcceptFeedback with the method CanAcceptFeedback(PredictionClient client, PredictorFeedbackKind feedback). So a predictor implementation can be specific about whether it accepts each feedback.
3. Add the feedback event OnCommandLineExecuted. It provides a predictor the information about the execution result (success or failure) of the last accepted user input.
4. Update how delegate is created in CommandPrediction, to minimize the allocation of the delegate helper object.
5. Add more tests and fix the fragile test.

PR Context

1. The Az.Predictor team asked for the new feedback OnCommandExecuted, which provides the execution status (success or failure) of the last accepted user input.
2. A predictor implementation will need the information about the client type (terminal, editor) to properly serve those 2 different scenarios, so we need to use a type to represent the client.

PR Checklist

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• This PR is ready to merge and is not Work in Progress.
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• Breaking changes
  • None
  • OR
  • Experimental feature(s) needed
    • Experimental feature name(s): PSSubsystemPluginModel
• User-facing changes
  • Not Applicable
  • OR
  • Documentation needed
    • Issue filed:
• Testing - New and feature
  • N/A or can only be tested interactively
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  • Make sure you've added a new test if existing tests do not effectively test the code changed
• Tooling
  • I have considered the user experience from a tooling perspective and don't believe tooling will be impacted.