Improve note linking search store

[cloverich]

Because of extreme time constraints I implemented note searching in #223 in the laziest way possible, recycling the existing search store. It worked great for the user-facing needs but if / when I ever have more then one-hour blocks to work on the app, or maybe after the key features are shipped, should come back and clean this up

• Use a custom store or improve (minimize) the interface used by each component
• Debounce the search
• Consider how the design will work when its network based (assuming I ever ship hosted notes)