Assessment: Fix the loss of submission text due to overlapping manual text blocks

[terlan98]

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.

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.
• I followed the coding and design guidelines.

Motivation and Context

Closes #6903

Description

Removed the console error for the case when manual text blocks were overlapping. Instead, added some code to handle the case as follows: determine the block that has a feedback assigned to it and add a new text block, if needed, to ensure that the block of the new feedback does not hijack some of the existing text.

Steps for Testing

Prerequisites:

• 1 Text Exercise with a submission ready for assessment
• 1 Tutor

1. Log in to Artemis as Tutor
2. Go to Course Management -> Assessment Dashboard -> Exercise Dashboard of the text exercise
3. Start an assessment
4. Select a specific portion of the text, by holding the alt/option key. Let's call the selected range [r1, r2]
5. Add some feedback and save
6. Refresh the page
7. Verify that you see your feedback
8. Delete the feedback
9. Again, hold alt/option key to select a different range of text. BUT, make sure that the new range overlaps with [r1, r2]
10. Add some feedback and save
11. Refresh the page
12. Verify that you can see your new feedback

Review Progress

Performance Review

• I confirm that the client changes (in particular related to REST calls and UI responsiveness) are implemented with a very good performance

Code Review

• Code Review 1
• Code Review 2

Manual Tests

• Test 1
• Test 2

Test Coverage

Client

Class/File	Line Coverage	Confirmation (assert/expect)
text-assessment-base.component.ts	84%	✅

[JohannesStoehr]

Can you also add a test for this bug?

[jakubriegel]

Code with test LGTM 👍🏻

Works on ts4

[JohannesStoehr]

Thanks for adding the test. Code looks good to me 👍

[tobias-lippert]

tested on ts4. Works as described.

[pal03377]

Code looks good to me 🎉 I also tested it again on TS4 to get a better feel of what the code is doing.