Headings must have an appropriate relative hierarchy to other headings on the same page.

[hostle83]

Describe the bug
Heading levels on a page should be applied structurally and hierarchically, without skipping levels. E.g. not displaying an <h1> followed by an <h3>; <h1> should be followed by <h2> followed by <h3> and so forth, without skipping levels. See also: https://www.w3.org/WAI/tutorials/page-structure/headings/

To Reproduce
Steps to reproduce the behavior:
As an example, on https://sandbox.dspace.org/entities/orgunit/17f528b5-cc95-4207-81c7-b7fce3b2ccfe, heading levels are skipped

Expected behavior
Heading levels should not be skipped

Related work

[atarix83]

@tdonohue @hostle83

4science is interested in working on this task.
We should try to fix wherever this problem is reported, not only in the mentioned item page. Estimation is about 6h