Increase the debounce of Issue Suggestions

What does this MR do?

This increase st he debounce for issue suggestion requests to 1000ms. This is to reduce the number of API requests sent.

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer