Replace multi-line string concatenations with text blocks for better readability #21417

I noticed that string concatenation is frequently used (here, for example) where text blocks would be much more readable and maintainable.

I suggest replacing these cases with text blocks.

I'd like to propose the following steps:

1. Find all uses — Identify all instances of string concatenation.
2. Analyze each case — Determine whether each case is a good candidate for a text block or if a StringBuilder would be more appropriate.
3. Set up a linting rule — (Optional) Consider adding a checkstyle rule (or similar) to prevent using concatenation in the future.
4. Create a list of violations — Provide a list of files/methods that need to be changed, so the work can be split or tracked.