Search alert designs

Created by: rrhyne

Search alerts tend to contain too much content for the alert area to properly display.

Redesign how search displays these alerts to work with the new alert styles by clearly stating the alert and its description, then move the helper content outside of the alert.

Example searches: https://sourcegraph.test:3443/search?q=repo%3A%5Egithub%5C.com%2Fsourcegraph%2Fsourcegraph%24&patternType=literal&c=Test%2Fsandbox

https://sourcegraph.com/search?q=context:global+repo:sourcegraph/sourcegraph+after:yesterday+type:diff+repo:typing+replaces+the+string+without+selecting++&patternType=literal