Header / Footer "major" accessibility issues that may not need design

[ndushay]

From https://docs.google.com/spreadsheets/d/1Fs5sY1zgpovWVdHMqpJWRu2Zvyr53jw7, "major" accessibility issues in the Header or Footer that we can fix without design changes.

Note that solutions may be suggested in https://docs.google.com/spreadsheets/d/1Fs5sY1zgpovWVdHMqpJWRu2Zvyr53jw7.

These can be separate PRs, and/or split into separate tickets.

• The image link with the logo for Stanford Libraries has an aria-label in addition to an image with alternative text and both instances have a value of "Stanford Digital Repository" without including the visible Libraries text. (also: "There are images with an alternative text that does not provide a meaningful equivalent. The "Stanford Libraries" logo has "Stanford Digital Repository" as the alternative text.") See Header / footer logo accessibility #3177
• (I think this pertains to the clickable images in the header or footer) - There are custom controls that do not provide textual name (link or button label, form label text), role (i.e. identify as button, link, text field, etc.), and/or state information (i.e. "expanded", "collapsed", selected, current).
  Although the information images receive keyboard focus, the tooltip information is not conveyed to all assistive technology users, such as NVDA users on Firefox and VoiceOver users on Safari.
• Help link: There are common input fields that lack autocomplete attributes to communicate their purpose programmatically: the "what is your name" and "what is your email address" fields in the main screen and in the Help dialog.
• Help modal: There are common input fields that lack autocomplete attributes to communicate their purpose programmatically: the "what is your name" and "what is your email address" fields in the first-time-user screen and in the Help dialog. Also in Welcome page: "major" accessibility issues that may not need design #3171
• Terms of Deposit modal dialog: Within the Terms of Deposit dialog, the list of links should be structured as a list: lists styled to look like a list should be indicated as such programmatically.
• (Minor level) There are images with an alternative text that does not provide a meaningful equivalent. The "Stanford Libraries" logo has "Stanford Digital Repository" as the alternative text.
• (Minor level) There are links that cause dialogs to open, but this behavior is not indicated ahead of time.