Additional tests for the import wizard (#11273)

* Setting up tests on import extension

* -Added API wrappers for all the azdata and vscode APIs to make them easily mockable
-Added some unit tests for the import extension
-Some code logic separations

* -added code report for the import extension in ci

* Did some more code refractoring

* -Added json report generation

* updated vscodetestcoverage to latest version in import extension.

* -remove duplicate codecoverageConfig.json

* -Added some modifyColumnPage tests

* pushing temp changes

* -Added some more testcases

* -Added tests using available vscode and azdata apis

* some minor comment change

* removed unnecessary test

* added accidently removed test

* Added some comments

* fixed some broken tests and added comments in fileConfigPage

* code clean up and some more comments

* fixed the prosePreviewPage test and the download test

* added getter and setters

* Increasing timeout and fixing a comment

* removed unnecessary comments and some other code cleanup

* Deleting dotnet files before redownloading them

* - made changes in the PR
- Moved extensioncode to utils.test for better reusability

* added some 'should' messages

extensions/import/src/test/services/serviceClient.test.ts

@@ -16,4 +16,3 @@ describe('Service utitlities test', function () {
 		should(ensure({ 'testkey': 'testval' }, 'testkey')).equal('testval');
 	});
 });
-