deposit-ui: fix sections config and form feedback to not use DOM

[slint]

We're currently using the DOM API (e.g. document.querySelectorall(".invenio-accordion-field");) to find all the form accordion section IDs and their form fields, to group them when displaying the form feedback banner at the top of the form.

This is a bad practice in React, which can cause rendering issues down the line. We should refactor this logic to use a React-compatible way for:

• Defining form sections config at a higher level. This should take into account:
  • Custom fields config in the form
  • Any customizations that instances make to the form, so that e.g. new fields and sections are properly registered
• Passing the defined sections config to:
  • The accordion section components
  • The form feedback banner component