Adding Execution Plan Editor to ADS (#18696)

* Pushing Execution Plan Editor

* Renaming class
Handling error

* Awaiting for handlers to be registered

* Addressing some PR comments

* Fixing return type for provider

* Fixing editor id and removing unnecessary overrides

* Adding a namespace

* adding execution plan namespace

* Adding protocol comment

* Fixing if logic

* Fixing error message

* Cleaning up code

* cleanup code

* Adding help comments

* Fixing method call

* Using path.ts to get the base file name

* converting to lambda functions

* Adding comment for run action

* Fixing pr comments

* Fixing editor label

* Fixing doc comments

* Adding some more comments

* Fixign branding in comments

src/sql/platform/capabilities/common/capabilitiesService.ts

@@ -28,6 +28,7 @@ export interface ConnectionProviderProperties {
 	azureResource?: string;
 	connectionOptions: azdata.ConnectionOption[];
 	isQueryProvider?: boolean;
+	supportedExecutionPlanFileExtensions?: string[];
 }
 
 export interface ProviderFeatures {