Improves support for long build traces:

What does this MR do?

• Change LIMIT_SIZE to 500 KiB, 50 seems too small
• Adds to truncate message a link to raw: raw_namespace_project_build_path(@project.namespace, @project, @build),
• Shows size in KiB instead of bytes
• Removes truncated logic - message should be visible every time size is less than the total.
• Removes transparent background
• Updates tests

Screenshots

Does this MR meet the acceptance criteria?

• Tests
  • Added for this feature/bug
  • All builds are passing
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #30696 (closed)