chore(ui): exports parseSearchParams (#10185)

As pointed out in #10164, parsing a `where` query from search params is
not exactly straightforward. Internally we rely on the `qs` module for
this, but it comes with a couple small nuances that are undocumented,
like the need to stringify them and specify depth. To standardize this,
we use a `parseSearchParams` utility internally that accepts the
`URLSearchParams` object that the `useSearchParams()` hook returns from
`next/navigation`. This PR exports that function for reuse and adds
JSDocs accordingly. Usage looks something like this:

```tsx
'use client'
import { useSearchParams } from 'next/navigation'
import { parseSearchParams } from '@payloadcms/ui'

function MyComponent() {
  const searchParams = useSearchParams()
  const parsedSearchParams = parseSearchParams(searchParams)
}
```