Adds coverage on supplier option to charge tax

[filipefurtad0]

What? Why?

• Relates to Add columns to "pay your supplier" report #13037.

We have basic coverage for both system and unit testing. There are a couple scenarios which would be relevant to additionally cover, at the unit level:

• supplier charges/does not charge tax -> tax values are included/excluded from the report
• supplier charges included tax -> tax values are included and calculated correctly on report
• distributor fees added to the incoming section of the OC -> these do not appear on the report

What should we test?

None.

Release notes

Changelog Category (reviewers may add a label for the release notes):

• User facing changes
• API changes (V0, V1, DFC or Webhook)
• Technical changes only
• Feature toggled

The title of the pull request will be included in the release notes.

Dependencies

Documentation updates

[mkllnk]

Great work! Nice to have all this covered.