[AOSS-1135] Ajax submit and callback updates
[AOSS-1135] Ajax submit and callback updates

- ajaxFormSubmit.js
  - replace .attr('data-...') references to .data('...')
  - add 'data-target-success' add 'data-target-error' attributes
    -  selector of elements found within the element specified in data-container and are used by the relative  callbacks
  - add reference to [ajaxCallbacks.helpers.]base object, defined in ajaxCallbacks.js

 ajaxCallbacks.js
  - add dataTableSubmitResponse callback
  - rename clientAccessResponse callback to 'emailFormResponse'
     - update success callback to reset form values to empty on elements which aren't "email" type (not just explicit for  name=payeref)
  - refactor clientAccessResponse callback to use [ajaxCallbacks.helpers.]base objects for common code

  - update .helpers:
     - general:
        - change .error class references to use .form-field--error
     - update 'setDomHtml':
        - swap target and node order for prependTo, appendTo and insertXxx methods
     - update 'insertResponseHtml' :
        - remove redundant references to missing client form
     - update 'insertFullPageErrorHtml' :
        - full page error response markup
     - update 'insertServiceErrorHtml'
        - remove redundant references to client access form
     - remove redundant 'bindEvents' helper

  - update .helpers.utilities
     - add 'hasSessionLapsed' to encapsulate common code for session time-out state
     - add 'showLogin' to encapsulate common code for redirection to login page
     - add 'setFormState' to disable/enable element(s) of all form(s) or button object
     - add tests for above .helpers.utilities additions

hmrc/assets-frontend,hmrc/assets-frontend,hmrc/assets-frontend