When the Title is focused, it doesn't use the same styling (border) as all other blocks. We need to update this to match.
Current State
Title focused:

vs. other type of block:

Proposed

Note: The way the Title currently sits in the editor, the border-top might not be visible. For the sake of simplicity and consistency with all other block types, let's match the styling (border: 1px solid ... on all four sides).