Add ability to change source and target to Schema Compare (#6026)

* add ability to change source and target

* addressing comments

* fixes after rebasing

* add check for user

* bump extension version

src/sql/azdata.proposed.d.ts

@@ -1747,6 +1747,7 @@ declare module 'azdata' {
 	export interface SchemaCompareEndpointInfo {
 		endpointType: SchemaCompareEndpointType;
 		packageFilePath: string;
+		serverDisplayName: string;
 		serverName: string;
 		databaseName: string;
 		ownerUri: string;