refactor: improve state management

...bsite/src/frontend/components/options/courses_selector.rs

aep-schedule-website/src/frontend/components/options/form.rs

aep-schedule-website/src/frontend/components/options/mod.rs

...-website/src/frontend/components/options/optimizations.rs

...chedule-website/src/frontend/components/options/search.rs

aep-schedule-website/src/frontend/components/options/todo.rs

aep-schedule-website/src/frontend/components/schedules.rs

aep-schedule-website/src/frontend/mod.rs

aep-schedule-website/src/frontend/pages/generator.rs

aep-schedule-website/src/frontend/state/mod.rs

aep-schedule-website/src/frontend/state/reactive_course.rs