Enforce vscode and ads version check when installing extensions (#4267)

* engine check when install extension

* gallery install/update and vsix install

* FIX COMMENTS

* Fix the detail not loading issue when version is invalid

* add more comments and adress PR comments

* add install telemetry for install from vsix scenario

* correct the name of the version property for telemetry

extensions/import/package.json

@@ -7,7 +7,7 @@
   "preview": true,
   "engines": {
     "vscode": "^1.25.0",
-    "sqlops": "*"
+    "azdata": "*"
   },
   "license": "https://raw.githubusercontent.com/Microsoft/azuredatastudio/master/extensions/import/Microsoft_SQL_Server_Import_Extension_and_Tools_Import_Flat_File_Preview.docx",
   "icon": "images/sqlserver.png",