cleanup, fixes and added comments

package-lock.json

package.json

src/components/Header.js

src/components/forms/AddSolutionForm.js

src/components/forms/SolutionDetailsForm.js

src/components/pages/ApplicantProfile.js

src/components/pages/Applications.js

src/components/pages/EventDetail.js

src/components/pages/Events.js

src/components/pages/Groups.js

src/components/pages/Homework.js

src/components/pages/News.js

src/components/pages/Profile.js

src/components/pages/Schedule.js

src/components/pages/Trainees.js

src/setupProxy.js