i18n: correct translation for "thread" in Dutch

[Rohit3523]

Proposed changes

In the Dutch translations, the term "discussie" was previously used for all thread-related terms, causing confusion. This pull request replaces "discussie" with "draad" for the singular and "draden" for the plural to accurately reflect thread-related terminology and improve clarity in the user interface.

Issue(s)

Closes #6062

How to test or reproduce

Screenshots

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• Improvement (non-breaking change which improves a current function)
• New feature (non-breaking change which adds functionality)
• Documentation update (if none of the other choices apply)

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works (if applicable)
• I have added necessary documentation (if applicable)
• Any dependent changes have been merged and published in downstream modules