`Development`: Use artemisApp as consistent prefix for translation keys

[Strohgelaender]

Checklist

General

• [ ] I tested all changes and their related features with all corresponding user types on a test server.
• [ ] This is a small issue that I tested locally and was confirmed by another developer on a test server.
• [x] I chose a title conforming to the naming conventions for pull requests.

Client

• [x] I followed the coding and design guidelines.

Motivation and Context

@Santia-go noticed that modeling exercises don't use the artemisApp prefix for its translation key. This PR fixes this inconsistency for multiple cases.

Description

There are still a few files left that don't start with artemisApp. These are files like home, error, alert, etc. which are not direct features of Artemis. All other files that refer to Artemis features should now use the artemisApp prefix.

Steps for Testing

1. Pease review the codebase to check for places where I could have missed some translations.

2. Test the following components and check if all strings are correctly displayed in both German and English.

• User Management
• Organisation Management
• Modeling Exercises (the whole lifecycle, participating, assessment, complaints)
• Quiz-Statistics

Review Progress

Code Review

• [ ] Review 1
• [ ] Review 2

Manual Tests

• [ ] Test 1
• [ ] Test 2

[Strohgelaender]

@nairaarnez Thanks for the review. This PR is only about refactoring the translation keys. I don't want to change the values as well since this PR is already quite big and should not get even bigger.

[Strohgelaender]

@ge65cer I did not touch error.json in the other PR, they should not conflict each other. We also cannot add the prefix to error.json because it contains translations for non-Artemis error keys.

[jpbernius]

Unfortunately, this PR broke two quiz-related test cases. Fixed in a4ed66d.