Feature/cms backend (#776)

* First cut of CMS get Server Api - returns only names

* Adding Proper naming and some more functions

* Adding add remove Server and tests for it

* Changing relative path to derive from KeyChain.Urn and Nuget update

* Adding async thread for requests

* Addressing CR comments and adding one more test

* Adressed PR comments around naming

src/Microsoft.SqlTools.ServiceLayer/Connection/ConnectionService.cs

@@ -1284,7 +1284,7 @@ namespace Microsoft.SqlTools.ServiceLayer.Connection
                 {
                     await requestContext.SendResult(ParseConnectionString(connectionString));
                 }
-                catch (Exception e)
+                catch (Exception)
                 {
                     // If theres an error in the parse, it means we just can't parse, so we return undefined
                     // rather than an error.