Support alt text for images added through Appearance Menu

[laritakr]

Descriptive summary

Contribute back Accessibility changes:

• [ ] Add the ability to add alt text for each of images added through Accessibility menu.

The following home page of each theme should have an alt text, if one is set:

• [ ] Logos
• [ ] Banner Image (use title, since alt isn't valid for background images set in CSS)

Rationale

Accessibility issue remediation

Expected behavior

Actual behavior

Steps to reproduce the behavior

Related work

Link to related tickets or prior related work here. https://gitlab.com/notch8/utk-hyku/-/issues/54