Migration: NgRx Component Store

Da das FE doch recht komplex geworden ist, wurde ngrx für die Zustandsverwaltung eingebunden. Das ist ein Sammelticket für die Migration der bestehenden Komponenten.

• EditExercise
• NewExercise

added refactor label

assigned to @fischer

added #156 (closed) as child task

added #157 (closed) as child task

added #158 (closed) as child task

added #159 (closed) as child task

added #160 (closed) as child task

added #161 (closed) as child task

mentioned in merge request !70 (merged)

added #162 (closed) as child task

added #163 (closed) as child task

changed the description

marked the checklist item EditExercise as completed

marked the checklist item NewExercise as completed

changed milestone to %2.1.0

closed