Display reusable block name in locations where the block appears

[jameskoster]

There is a proposal in #27876 to display template part names in the toolbar, block list view, and breadcrumb. I believe we can also consider implementing this pattern for reusable blocks in order establish alignment across similar features. These changes increase clarity around exactly what it is you're editing.

In making this change, we may need to move the "Convert to regular blocks" link to the ellipsis menu, to avoid overloading the toolbar.

Before

After