Allow for field settings to be shared across View Modes

Problem/Motivation

There are many use-cases where a field's display setting needs to be shared for a specific view mode across content types.

Example: A featured image field

• Renders as 4x1 for full-content view mode
• Renders as 16x9 for a card view mode
• Renders as 1x1 for a tile view mode

Proposed resolution

Add a third "Shared field display mode" for View modes.