Integrate first SQL Notebooks Bits into Master (#3679)

* First crack tsql notebook (no output rendered yet)

* getting messages back

* intellisense working first cell, no connection errors

* sql notebook cell output functioning

* Latest SQL noteobook changes

* Undo change to launch.json

* Plumbing providers through

* Kernels shown from multiple providers, can switch between them. No mementos yet

* Ensure we have a feature flag for SQL notebooks, ensure existing functionality still works

* Fix tslint duplicate imports issue

* Addressing PR comments

* second round of PR feedback to cleanup notebook service manager code

* merge latest from master

src/sql/services/notebook/notebookRegistry.ts

@@ -18,11 +18,12 @@ export const Extensions = {
 export interface NotebookProviderRegistration {
 	provider: string;
 	fileExtensions: string | string[];
+	standardKernels: string | string[];
 }
 
 let notebookProviderType: IJSONSchema = {
 	type: 'object',
-	default: { provider: '', fileExtensions: [] },
+	default: { provider: '', fileExtensions: [], standardKernels: [] },
 	properties: {
 		provider: {
 			description: localize('carbon.extension.contributes.notebook.provider', 'Identifier of the notebook provider.'),
@@ -39,6 +40,18 @@ let notebookProviderType: IJSONSchema = {
 					}
 				}
 			]
+		},
+		standardKernels: {
+			description: localize('carbon.extension.contributes.notebook.standardKernels', 'What kernels should be standard with this notebook provider'),
+			oneOf: [
+				{ type: 'string' },
+				{
+					type: 'array',
+					items: {
+						type: 'string'
+					}
+				}
+			]
 		}
 	}
 };