feat: let VisualEditor accept dynamic uischema instead of hardcoding

[yeze322]

Description

closes #1984

To support the scenario that users can customize their own editor schema under a bot project, Visual Editor should have the capability to consume dynamic passed-in uischema instead of consume a hardcoded one.

This PR refactor the schema provider logic in Visual Editor and make it possible to accept dynamic uischema from external sources.

// 1 - create a schema provider
import schemaV1 from './schemas/v1';

const schemaV1Provider = new SchemaProvider(schemaV1);
const SendActivity = schemaV1Provider.get('Microsoft.SendActivity');


// 2 - pass the provider through context
<UISchemaContext.Provider value={uiSchemaV1Provider}>
  <VisualEditor />
<UISchemaContext.Provider>

// 3 - consume the schema
const Action = (props) => {
  const schemaProvider = useContext(UISchemaProvider)
  const sendActivitySchema = schemaProvider.get('Microsoft.SendActivity');
  return renderWithSchema(sendActivitySchema);
}

Task Item

#1984

Screenshots