* Connect with different properties should actually change context
- Up to now, calling Connect for a previously-connected URI would disconnect, then reconnect ot the original (not new) target. WIth these changes we handle changes to database name or other key properties by updating the ConnectionInfo and connecting to the new target
- Some interesting scenarios are raised by our API, notably that an empty database name maps to the default DB (which we know nothing about). This limits the new feature such that only if the DB Name is specified, we'll change the connection. Hence 2 calls to an empty DB will not result in a DB change.
Additional changes:
- After discussion with Ben, we're simplifying the cancellation logic. He had made changes to support this, so the main update is that we dispose the token in the final block after its last use (hence avoiding a disposed exception) and clean up the number of Waits required since we already have async cancellation support
- Factored some logic such that the OnConnection callback isn't invoked until after we've updated the database name in the GetConnectionCompleteParams method. Again, this supports reporting the actual DB name instead of leaving it blank for default DB requests.
* PR comment fixes
* Add CancelTokenKey for uniquely identifying cancelations of Connections associated with an OwnerUri and ConnectionType string.
* Update ConnectionInfo to use ConcurrentDictionary of DbConnection instances. Add wrapper functions for the ConcurrentDictionary.
* Refactor Connect and Disconnect in ConnectionService.
* Update ConnectionService: Handle multiple connections per ConnectionInfo. Handle cancelation tokens uniquely identified with CancelTokenKey. Add GetOrOpenConnection() for other services to request an existing or create a new DbConnection.
* Add ConnectionType.cs for ConnectionType strings.
* Add ConnectionType string to ConnectParams, ConnectionCompleteNotification, DisconnectParams.
* Update Query ExecuteInternal to use the dedicated query connection and GetOrOpenConnection().
* Update test library to account for multiple connections in ConnectionInfo.
* Write tests ensuring multiple connections don’t create redundant data.
* Write tests ensuring database changes affect all connections of a given ConnectionInfo.
* Write tests for TRANSACTION statements and temp tables.
* experimental showplan implementation (tools side only)
* fix for redundant massages from showplan executions
* moved showplan batches to new variables to make it less confusing
* returns showplan as part of batch summary with in each result summary
* cleaned up showplan resultsets
* cleaning up code and making showplan var optional
* changes all var names to showplan
* adding estimated support
* small fixes
* updatin var names and adding EPOptions struct
* adding ssms execution plan logic based on server types
* adding special actions logic
* removing redundant name changes
* execution plan query handler added
* cleaning up functions and data structures
* seperated special actions into its own class
* cleaning up special actions
* cleaning up code
* small new line fixes
* commenting out pre-yukon code
* removing all pre yukon code
* last yukon code commented out
* fixes broken tests
* adding related unit tests; integration tests incoming
* finishing tests and cleaning up code
* semantic changes
* cleaning up semantics
* changes and test fixes, also adding new exceptions into RS
* fixing special actions and cleaning up request logic
* fixing comment to trigger new build
* triggering another build
* fixed up specialaction and added tests for it
