Describe the bug

If there is a JQUI datepicker above a TinyMCE text field, the datepicker dropdown is hidden beneath the text field toolbar:

Janeway version

v1.5.1-RC-6+

Proposed solution

• Replace all instances of JQUI datepicker with the standard HTML picker, provisionally, until we have a back-office design system for these.
• Replace all instances of JQUI datepicker and timepicker with a new DateTimeField modification that uses datetime-local.

In scope

• src/templates/admin/core/manager/news/index.html: {% include "elements/datepicker.html" with target="#id_start_display" %}
• src/templates/admin/core/manager/news/index.html: {% include "elements/datepicker.html" with target="#id_end_display" %}
• src/templates/admin/review/add_review_assignment.html: {% include "elements/datepicker.html" with target="#id_date_due" %}
• src/templates/admin/review/revision/request_revisions_notification.html:{% include "elements/datepicker.html" with target="#id_date_due" %}
• src/templates/admin/review/revision/edit_revision_request.html: {% include "elements/datepicker.html" with target="#id_date_due" %}
• src/templates/admin/review/revision/request_revisions.html: {% include "elements/datepicker.html" with target="#id_date_due" %}
• src/templates/admin/review/edit_review.html: {% include "elements/datepicker.html" with target="#id_date_due" %}
• src/templates/admin/copyediting/add_copyeditor_assignment.html: {% include "elements/datepicker.html" with target="#id_due" %}
• src/templates/admin/copyediting/editor_review.html: {% include "elements/datepicker.html" with target='#due' %}
• src/templates/admin/copyediting/edit_assignment.html: {% include "elements/datepicker.html" with target="#id_due" %}
• src/templates/admin/journal/publish_article.html: {% include "elements/datepicker.html" with target="#date" %}
• src/templates/admin/preprints/article.html: {% include "elements/datepicker.html" with target="#date" %}
• src/templates/admin/journal/publish_article.html: {% include "elements/timepicker.html" with target="#time" %}
• src/templates/admin/preprints/article.html: {% include "elements/timepicker.html" with target="#time" %}

Not in scope

• src/templates/admin/production/edit_typesetter_assignment.html: {% include "elements/datepicker.html" with target="#id_due" %}
• src/templates/admin/proofing/proofing_article.html: {% include "elements/datepicker.html" with target="#id_due" %}
• src/templates/admin/proofing/request_typesetting_changes.html: {% include "elements/datepicker.html" with target="#id_due" %}
• src/templates/admin/proofing/edit_proofing_assignment.html: {% include "elements/datepicker.html" with target="#id_due" %}