[8] Rework saving to use interface and enable testing

Remove automatic saving from model, feeds, feed providers, articles and collections

ToDo

Custom:

• Remove automatic saving from model, feeds, feed providers, articles and collections
• Add new Interface to correctly save every component

Defaults:

• Report Changes in UML
• Report Changes in Wireframes
• Write Tests for every new non-view class

Acceptance criteria

Custom:

• Saving behaves the same but without saving as soon as anything is created

Defaults:

• Naming Convention for Classes, Functions and Variables are met
• Comments are sufficient
• Tests for every new non-view class are created and used in testing

Effort:

8

added Sprint-Backlog label

changed the description

mentioned in commit 06fe4b5b

mentioned in commit df8178ad

assigned to @s75706

added Sprint 12 label

mentioned in commit 2caa6940

mentioned in commit 105d95b2

mentioned in commit 0d9f47eb

mentioned in commit 2ec93223

mentioned in commit 5d3b7af8

mentioned in commit 46793a8c

mentioned in commit a7816091

mentioned in commit 592ce41e

mentioned in commit c92467bd

added To Integrate label and removed Sprint-Backlog label

mentioned in commit 085e219d

marked the checklist item Remove automatic saving from model, feeds, feed providers, articles and collections as completed

marked the checklist item Add new Interface to correctly save every component as completed

marked the checklist item Report Changes in UML as completed