[Page header] Edit title A11y improvements

[kingtraceyj]

After review with a11y team, improvements can be made to the edit title prop for Page Header

Requirements
Header should not not be automatically editable on focus
Default state could be a persistent edit icon next to title instead of reveal on hover (maybe this could be optional)

Tasks

• Draft more accessible ways to edit title
• Get feedback from a11y team
• Chose design direction
• Make specs

Open questions
Should we update the current header alongside the new page header version?
How will this affect the update and edit pattern?