We already have a basic display of the list of diagrams. This ticket involves updating the list to more accurately match the designs, show some more information about diagrams, and have search/sorting functionality.

Figma designs: https://www.figma.com/design/nz84lFaVMLqq9ih4ZJtuP6/Data-modeling-viz-tool?node-id=2340-59573&t=303js43kstBEocuE-1 

Let's not use the `VirtualGrid` to display the cards, instead let's use some basic styles to get the diagram cards in a grid.

Add to the card the date when the diagram was last modified, which is the timestamp from the most recent edit in the edits array (last element). 

Build a toolbar into the diagrams list that has search functionality, sorting, and a button to create a new diagram. 

This behaves similar to the my-queries page’s search functionality and sorting: https://github.com/mongodb-js/compass/blob/1086d07de3afb2d52cd55eea00ac2da1d62ec753/packages/compass-saved-aggregations-queries/src/components/aggregations-queries-list.tsx#L247