Delete INVOICE_EXTENDED_WORKFLOW and Finance 2 role?

[frjo]

OTF is not planing to use the INVOICE_EXTENDED_WORKFLOW, can we delete all related code completely?

Is the Finance 2 "role" needed? If not we can remove that as well.

[frjo]

@wes-otf I made a test PR here #4122

If we do not need Finance 2 then this PR removes a lot of code and complexity.

[wes-otf]

this slipped by me last week but I don't believe we OTF needs it. Will confirm today though so we can get this through.