Ignore search param for autosave on issue new form

What does this MR do and why?

This change is part of #331831 (closed), and ensures that the title and description fields are kept populated in the new Issue form when changing Issue types.

Previously when changing issue types the form would be cleared and users would need to populate those fields again.

Further changes to populate other fields (Labels, milestone, etc) will be done in subsequent MRs.

Screenshots or screen recordings

Before:

After:

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

MR acceptance checklist

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Related to #331831 (closed)