Allow to ignore initialParams when using useSearchParams

[mauricedoepke]

When you call the app via a link, e.g.

myapp://items/1234

while you defined these routes:

app
 _layout.js
  items
    index.js
    [itemId].js

The itemId property will be set as an initialParam in react navigation. This means even if you navigate to /items which might be a list of items, useSearchParams will still return 1234 as itemId.
When you navigate to a another item, the initial param will be propperly shadowed by the correct id, but once you navigate back to the list page useSearchParams will again return 1234 as itemId.

This is problematic if some components of your app rely on itemId being undefined if no specific item is displayed.

I think it would be nice to have some option like useSearchParams({ignoreInitialParams: true) to deal with this case.