ui: MySQL icon is almost invisible on the dark theme; Mongo collection order differs between tree and list #1824

Problem

Two small things from a pass over the local MySQL and MongoDB connections (dev at 25c766c):

• The MySQL dolphin logo on the connection row and in the form header is dark blue on the near-black sidebar and barely readable (the PostgreSQL and MongoDB logos are fine).
• MongoDB collections are listed alphabetically in the sidebar (orders, products, types_showcase, users) and in a different order in the collections view of the same database (types_showcase, products, orders, users, which is by size).

Expected

A theme-aware (light on dark) variant of the MySQL logo; the same order in both lists, or an explicit sort control in the view.