Add display text field to link menu

**Problem Statement**
As a user, I would like an easier way to update the display text of my hyperlink in my doc, so I can make these types of changes more efficiently.

**Acceptance Criteria**
**Non-functional**
- add an additional field to the link menu
- new field placeholder text should read as "display text"

**functional**
- when a user makes an edit to an hyperlink, the "display text" field should be available as an additional option
- the display text in the document should mirror whats in this field and vice versa
- when a user edits the "display text" field, the text in the document should update accordingly

**Mock up:**

Start by locating the link menu and hyperlink editing entry points in the authoring interface. Verify how the document's hyperlink text is read and updated, then implement the additional "display text" field so both representations stay synchronized and validate the behavior against the listed acceptance criteria.

Written by the indexing model from the issue text.