[REF] Cleanup code to determine financial_type_id

[eileenmcnaughton]

Overview

[REF] Cleanup code to determine financial_type_id

Before

financial_type_id is hard to track as it is passed from array to array & calculated twice

After

retrieved via a consistent function that uses a utils class to retrieve the cached information.

Test cover

Technical Details

Financial type id is really simple on this form - it's either required or
it can be determined form the price set.

However, the code passes the financial_type_id from array to array, calculating
it in more than one place which rather hides the underlying simplicity of it.

This retrieves it using a function that does the same from anywhere in the code.

Note that if someone tried to add it before this->order is built it would
hard fail & kill a bunch of tests. this->order is built at the start of the
submit routine

Comments

[civibot]

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[eileenmcnaughton]

@monishdeb are you able to merge this - I think it's fairly straight forward/ covered by the test

[monishdeb]

Patch looks good. Tested on local.