[Accessibility] Implement Contextual Help Tooltips site wide

[hostle83]

Describe the bug

According to Section 508, technologies such as DSpace "shall provide features making its use by individuals with limited cognitive, language, and learning abilities simpler and easier".

This can be done in several ways. One way to achieve this is by providing tooltips. This was already implemented on the "Edit group" pages: here, users have the ability to toggle context help on/off.

(See https://demo.dspace.org/access-control/groups/f2c7eb75-aec0-4604-ab7f-6676723818ad/edit)

It would be great to implement this feature site-wide, in order to make the different labels and features of DSpace more understandable to those who have limited cognitive, language, and learning abilities.

Note: it is important to make these tooltips readable to screen readers and keyboard navigationable.

Examples for terminology in DSpace that could benefit from tooltips are:

Communities (what are they?)
Collections (what are they?)
Processes (what are they?)
Terminology when viewing an item, such as

Publisher
Research Projects
Organizational Units
URI

Any other term that would be difficult or challenging to understand by someone with a learning disability (i.e. any term that is technical in nature).

Related PRs:

Contextual Help Tooltips visible by default: #2263
Contextual Help (closed): #762
Add link to Documentation from within DSpace User Interface: #3320

[Andrea-Guevara]

Good morning @hostle83 and @tdonohue! We at Neki-it have been analyzing this issue and wanted to know if the help texts are already defined or if the goal is to add the “*dsContextHelp” directive with alternative texts?

[tdonohue]

@Andrea-Guevara : At this time, no help text is already defined. Therefore, this task would require both writing help text and ensuring that the proper "dsContextHelp" directives appear on the given pages.

I don't expect this task will be built in a single PR, because there are so many pages in DSpace. So, even small improvements to specific areas of DSpace are welcome. It may require many PRs to had useful help text sitewide.