Adding like filter and removing contains to OE filtering (#2105)

* Adding startswith and like filter

* Adding ends with

* Adding tests

* Remove null and not null

* Fixing string

* Update test/Microsoft.SqlTools.ServiceLayer.UnitTests/ObjectExplorer/NodeFilterTests.cs

Co-authored-by: Charles Gagnon <chgagnon@microsoft.com>

* Update test/Microsoft.SqlTools.ServiceLayer.UnitTests/ObjectExplorer/NodeFilterTests.cs

Co-authored-by: Charles Gagnon <chgagnon@microsoft.com>

* Adding back contains, starts with and ends with

* Properly escaping chars for like based filters

* Adding some comments regarding escape characters

* Using generated regex

* removing additional class

* Adding extra auth type that was causing the tests to error out

* Fixing regex

* Adding integration tests

* Fixing unit tests

* Making fluent assertions

---------

Co-authored-by: Charles Gagnon <chgagnon@microsoft.com>

test/Microsoft.SqlTools.ServiceLayer.Test.Common/TestServerIdentity.cs

@@ -29,6 +29,7 @@ namespace Microsoft.SqlTools.ServiceLayer.Test.Common
     public enum AuthenticationType
     {
         Integrated,
-        SqlLogin
+        SqlLogin,
+        AzureMFA
     }
 }