Programming exercises: Add Dart programming exercise template

[magaupp]

Checklist

General

• I tested all changes and their related features with all corresponding user types on a test server.
• Language: I followed the guidelines for inclusive, diversity-sensitive, and appreciative language.
• I chose a title conforming to the naming conventions for pull requests.

Server

• Important: I implemented the changes with a very good performance and prevented too many (unnecessary) and too complex database calls.
• I strictly followed the server coding and design guidelines.

Client

• Important: I implemented the changes with a very good performance, prevented too many (unnecessary) REST calls and made sure the UI is responsive, even with large data (e.g. using paging).
• I strictly followed the client coding and design guidelines.
• I documented the TypeScript code using JSDoc style.
• I translated all newly inserted strings into English and German.

Changes affecting Programming Exercises

• High priority: I tested all changes and their related features with all corresponding user types on a test server configured with the integrated lifecycle setup (LocalVC and LocalCI).
• I tested all changes and their related features with all corresponding user types on a test server configured with Gitlab and Jenkins.

Description

This PR adds a programming exercise template for the Dart language. The exercise uses the usual strategy pattern example.
Testing uses the standard package:test.
The Docker image is based on the official dart image and installs package:junitreport for the conversion to the JUnit format and XmlStarlet to strip the JUnit output of the useless message attribute and fall back to the stacktrace.

Steps for Testing

Prerequisites:

• 1 Instructor

1. Navigate to the exercise creation page
2. Select Dart for the language
3. Verify that only valid lowercase Dart identifiers can be used for the package name
4. Fill out all necessary fields correctly and generate the exercise
5. Wait until the test results are available in the exercise details page
6. Verify that the template result passes 0/13 tests without build failure
7. Verify that the solution result passes 13/13 tests without build failure

Testserver States

You can manage test servers using Helios. Check environment statuses in the environment list. To deploy to a test server, go to the CI/CD page, find your PR or branch, and trigger the deployment.

Review Progress

Code Review

• Code Review 1
• Code Review 2

Manual Tests

• Test 1
• Test 2

Summary by CodeRabbit

• New Features

  • Introduced Dart as a supported programming language for programming exercises.
  • Added Dart-specific package name validation and integration within continuous integration and build workflows.
  • Provided new Dart exercise templates featuring examples for sorting algorithms.

• Documentation

  • Updated user guides and localization content to include guidelines for Dart exercises.

• Tests

  • Expanded test suites to verify Dart exercise functionality and sorting behavior.

[az108]

Code 👍

[BBesrour]

tested on ts3, lgtm

[sachmii]

Tested on TS4, works just fine.

[flbrgit]

Tested on TS6, works as expected

[vinceclifford]

Looks good to me, works as expected. Tested on TS6.

[kevinfischer4]

Tested on TS5, package name validation and exercise creation work as expected 👍

[sawys777]

Retested on TS3, everything works as expected

[krusche]

Changes look good 👍