HEEDLS-496 Fix layout issues and incorrect button disabling

[AlexJacksonDS]

JIRA link

https://softwiretech.atlassian.net/browse/HEEDLS-496

Description

Fixed button being displayed when it shouldn't be. Fixed layout issues. Converted page to the new application setting system.

Screenshots

Delegate with no password has no button:

Delegate already admin has no button

Re-ordered elements at the top of the page

Updated email in use message

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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.

[livzorn]

Looks all good to me :)

[DanBloxham-sw]

Minor additional check to make unless I am missing something.

[DanBloxham-sw]

As we also hide the button when the delegate does not have a password set can we add another check here so the users can't get around it with URL manipulation.