chore: remove the 'all' option used for filtering product categories

[Gideonnn]

Context

The ProductCategoryEnum.All and categoryLabelByEnum All categories options have been removed, since they are no longer required for filtering the product categories on the browse covers screen.

Todo

• Clean up https://github.com/NexusMutual/frontend-next/pull/836 after getting this live. It now uses inlined copy-pasted versions of ProductCategoryEnum and categoryLabelByEnum