Partial code cleanup & testability improvement towards CRM-21177

[eileenmcnaughton]

Overview

This is a partial reviewer's commit of #11038 which pulls in the initial readability & testability commit.

Before

No test, patch of code harder to read

After

test added, code slightly more legible , larger pr closer to resolution

Technical Details

@GinkgoFJG #11038 is pretty daunting for a reviewer, on top of the fact it still has test fails. I pulled in the first 3 commits from it (although I had to comment out one line of the test for now) to start to chip away at it. I will set this to merge on pass as I have reviewed these commits - once that is done if you could rebase your PR

Comments

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• CRM-21177: Wrong interval of recurring payment for auto-renewing membership

[civibot]

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