Add global focus style on all primary buttons (see Get Started button on home page)

[johnrozan]

Feature Request
As a peoplemover user with a disability
I would like all focus states for primary buttons to be visually clearer
so that I know when I am focused on a particular button

Acceptance Criteria
Save button in Add New Space modal
Create button in Create New Space modal
Assign button in Assign a person modal
Save button in Edit person modal
Add button in Add New Person modal
Invite button in Invite others to edit modal
Save button in Edit Product modal
Add button in Add Product modal

Add a global style for primary buttons to inherit from.

Make it look like Get Started button on landing page.

Accessibility Criteria
Text and background color meets a minimum color contrast ratio of 4.5:1
All non-text content (e.g. images, icon) has alt text
Web page includes appropriate headings to communicate structure/hierarchy (h1>h2>h3)
All functionality is available to a keyboard
Focus styles are highly visible
Tab order is logical and aligns with the visual order
Voice over is understandable and logical
Aria labels are added to elements with no visible text
Decorative elements (e.g. non-informative icons) are hidden from screen readers
Form fields have appropriately coded labels that are visible during input
Links are visually identifiable and have a clear focus and active state
Notes