Search improvements

src/app/degree-planner/degree-planner.component.html

src/app/degree-planner/degree-planner.component.ts

src/app/degree-planner/services/api.service.ts

...ree-planner/shared/course-item/course-item.component.html

...egree-planner/shared/course-item/course-item.component.ts

src/app/degree-planner/store/effects/plan.effects.ts

src/app/degree-planner/store/selectors.ts

src/app/degree-planner/store/state.ts