MASQrauder

I think I've addressed all the feedback from the first and second reviews. I responded to comments in #429. I may understand what happened last time with the previous PR;...

* Removed database migration that is unnecessary. * Added `database_version_9_sql.txt` to create the database at version 9 with a null `start_block` defined. * I left the `set_configuration_command` to be resolved...

GH-606: Apply PR review 4 feedback changes I think I responded to all the view comments. If I missed any please let me know.

Summary (from AI Assistant) Changes 1. Changed accountant::mod.rs Adjusted the field new_start_block in struct ReceivedPayments to be of type `Option`. Altered multiple unit tests to reflect the new field type....