Better submissions table

src/app/services/submission.service.ts

src/app/shared/models/mixins.ts

src/app/shared/models/models.ts

src/app/shared/shared.module.ts

.../submission-list-view/submission-list-view.component.html

.../submission-list-view/submission-list-view.component.scss

...bmission-list-view/submission-list-view.component.spec.ts

...ed/submission-list-view/submission-list-view.component.ts

...p/shared/submissions-table/submissions-table.component.ts

...ubmissions/submission-list/submission-list.component.html

.../submissions/submission-list/submission-list.component.ts

src/app/submissions/submissions.module.ts