Add support for MS_Description documentation

[bujocek]

We are trying o transit development from SQL Server Management Studio to Visual Studio Code, but there is one crucial feature missing.
Our whole documentation is stored in MS_Description extended property for any table, stored procedure, column, view a.s.o.

In SSMS we use RedGate's SQLPrompt plugin and it provides us with enhanced tooltips when we hover over a DB object. These tooltips always contain MS_Description extended property in it.

As described in following documentation:

Full docu: https://documentation.red-gate.com/sp/sql-code-completion-and-intellisense/using-the-object-definition-box-and-object-tooltips

In VSCode we can not quickly access our documentation and development without this documentation is very challenging.