fix: backend voucher individual code search

[Dominikrt]

Hi,

1. Why is this change necessary?

the individual voucher code search is broken, after a reload the store lose its filter

2. What does this change do, exactly?

the last filter get cleared bevor and not after the search method.

3. Describe each step to reproduce the issue or behaviour.

open a individual voucher and search for a code, after a list reload the filter gets cleared.

4. Please link to the relevant issues (if any).

5. Which documentation changes (if any) need to be made because of this PR?

6. Checklist

• I have written tests and verified that they fail without my change
• I have squashed any insignificant commits
• This change has comments for package types, values, functions, and non-obvious lines of code
• I have read the contribution requirements and fulfil them.

[github-actions]

	Warnings
⚠️	The Pull Request doesn't contain any changes to the Upgrade file

[mitelg]

thanks again for your contribution @Dominikrt 👍🎉💙