feat: UI Schema - Recognizer

[yeze322]

Description

Use uischema to control which Recognizers can be used in Composer. Including

• Enable a new Recognizer in dropdown - by editing the uischema 'recognizer' part
• Edit the label name of a Recognizer in dropdown - by setting displayName
• Set a Recognizer as default Recognizer when creating dialog - by setting default: true
• Hide a Recognizer from dropdown - by setting disabled: true

Remainings

• When seeding a new Dialog, use the default recognizer described by uischema
• Integartion with publish flow (Will be covered in another PR)
• Code cleanup (//leak, //TODO)
• Fix the UT (broken by schema change)

Usage
(To make it simple, use sdk.override.uischema as an example.)

1. Open the sdk.override.uischema file under a bot project (DO use override schema due to plugin has higher priority than sdk.uischema. Will be moved to botbuilder component schema)
2. Paste these Recognizer options.

{
  "$schema": "https://schemas.botframework.com/schemas/ui/v1.0/ui.schema",
  "Microsoft.PVARecognizer": {
    "recognizer": {
      "displayName": "Default Recognizer (PVA)",
      "default": true
    }
  },
  "Microsoft.CrossTrainedRecognizerSet": {
    "recognizer": {
      "displayName": "Luis QnA Recognizer",
      "default": false
    }
  }
}

PVARecognizer will be added to dropdown menu.

Task Item

closes #4111

Screenshots

[cwhitten]

@yeze322 we want to allow PVA or another runtime to model the Default Recognizer to be their recognizer instead of our Luis + QnA cross-trained components. So the scenario is:

I can provide a schema + uischema that allows me to override the behavior & configuration of the default recognizer with my own behavior & configuration

In PVA's case they will essentially alias the Default Recognizer to be their PVARecognizer component because there are no additional build steps.

[yeze322]

@cwhitten Yes we can, I added a new field default: boolean to recognizer uischema.

Take the PVA scenario as an example, we want PVARecognizer become the default recognizer. We override the uischema with this JSON:

{
  "Microsoft.CrossTrainRecognizerSet": {
    "recognizer": {
      "displayName": "LUIS Recognizer",
      "default": false
    }
  },
  "Microsoft.PVA.Recognizer": {
    "recognizer": {
      "displayName": "Default Recognizer (PVA)",
      "default": true
    }
  }
}

[yeze322]

@liweitian There are several questions about issues left over from QnA PR in Andy's code review, could you answer them?