Disable greedy mode when matching filename

What does this MR do?

When parsing search results from file or blob content search, filename and content are split by a \x00\d+\x00/ delimiter. If the delimiter is present multiple times in the content, then filename contains longest possible regexp match, but in this case we want shortest match.

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• Internationalization required/considered
• End-to-end tests pass (package-and-qa manual pipeline job)

What are the relevant issue numbers?

Closes #44784 (closed)