Header: Implement mobile redesign

[alundgard]

This is a summary issue. There are a number of adjustments we'd like to implement for narrow viewports. Some of these already have issues in the component-library repository.

Mobile redesign

• All menu navigation links should appear in the hamburger dropdown. Header: All menu navigation links should appear in the hamburger dropdown #2772.
• Display the subtitle on mobile. Related to Exhibit sub-titles don't display on mobile devices #623.

The base header component can be found in “DLSS Components” Figma File: https://www.figma.com/design/K1syTsalaB1nlRftgOi0Pw/DLSS-Components?node-id=742-922&t=hezVZDhbDPM3h5IU-4

Component library

• Menu in header on mobile should open below the application title instead of in between the Stanford Libraries row and the application title row component-library#39
• Swap ordering of mobile menu links component-library#77
• Header mobile menu - should have X icon to close when it's opened component-library#38
• Left-align application title on mobile header view component-library#59

[dnoneill]

I feel like there is a lot of this ticket. I am going to start with the subtitle ticket and leave this free for someone else to pick up the other items.