HEEDLS-609 : Move ConfigHelper to the data project

[GeorgeBlackwell]

JIRA link

HEEDLS-609

Description

A technical debt ticket to move functionality from ConfigHelper to ConfigurationExtensions in the data project.

---

Developer checks

(Leave tasks unticked if they haven't been appropriate for your ticket.)

I have:

• Run the formatter and made sure there are no IDE errors.
• Written tests for the changes (accessibility tests, unit tests for controller, data services, services, view models, etc)
• Manually tested my work with and without JavaScript. Full manual testing guidelines can be found here: https://softwiretech.atlassian.net/wiki/spaces/HEE/pages/6703648740/Testing
• Updated/added documentation in Swiki and/or Readme. Links (if any) are below:
  • doc_1_here
• Updated my Jira ticket with information about other parts of the system that were touched as part of the MR and have to be sanity tested to ensure nothing’s broken.
• Scanned over my own MR to ensure everything is as expected.

[AlexJacksonDS]

There are some changes that I think should have been done that are not yet done, and some files are now in the wrong place following the changes.
Also a query about whether we've done the correct thing here for Steve.

[JBsoftwire]

I don't have any new comments to add to what Alex said, just to make sure you deal with the merge conflicts as well.

[AlexJacksonDS]

I think this looks good now, you've just still got another merge conflict to resolve since the last merge from master