Export code clean up - extract build row & getTransformed row off to ExportProcessor

[eileenmcnaughton]

Overview

Code cleanup in export class

Before

Code not extracted

After

Code extracted

Technical Details

@mattwire this is actually a pretty simple code moving PR - it should be fairly easy to verify by repeating the steps to extract locally. I think the jenkins tests should be pretty sufficient here as there is no logical change in this step

Comments

[civibot]

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[eileenmcnaughton]

@mattwire I also added this - #13120 which doesn't conflict with this so can be tested in conjunction

[eileenmcnaughton]

This is my working branch for follow ons https://github.com/civicrm/civicrm-core/compare/master...eileenmcnaughton:export_merge?expand=1

[mattwire]

I've tested this locally with a small dataset (207 contacts) and it works fine with/without this PR. The PR itself is extracting and moving code to the ExportProcessor class and creating a new function to build each row. There is a small risk that this could have a cumulative performance impact on large datasets but given that the functions called multiple times are cached (pseudoconstant and i18n singleton) that impact should be minimal. Ok to merge @eileenmcnaughton @seamuslee001

[eileenmcnaughton]

thanks @mattwire I'll push up another step later today