* Update client paid to date job:
* Backup Invoice HTML when invoice is marked as sent and paid
* Store HTML of invoice when invoice was paid
* Fix foreign keys in db schema
* V2 Endpoints for Company Migrations
* Fixes for tests
* Implement client/group/company level counters clientCounter, groupCounter and counter
* Implement functionalityfor customising the timing of invoice_number creation
* Add Jobs
* adjustments
* clean line items at the request layer
* Clean line items at the request layer