The code was using a two-way reference linking the database to the results and the results to the database.
However, this was not really used so it ended up just cluttering the code. With this commit, the results and databases are no longer keeping track of each other, and the only interaction is when the results are written to the database at the end of the operation.
To ensure result data is always written, this code has been moved into the controller, which will now flush the results for all operations. Prior to this, only some operations would write result data to the log.
The controller now also handles logic for cleaning old log data and invoking the vacuum command.
Fixed a bug due to using System.Text.Json where some attributes from NewtonSoft.Json were being applied and not picked up.
Rewrote all operation handlers to be async.
This moves the async/sync threshold out into the controller.
Fixed all the uses of cancellation token in the handlers to use the provided cancellation token.
Introduced a new ReusableTransaction that can be passed around, avoiding a ref parameter passing of the transaction instance.