Unnecessary search widget rebuilds

[M123-dev]

What

• While testing around a bit for The keyboard keeps opening when navigating from search results to individual products #800 I found some (Strange?) unnecessary rebuilds.

To Reproduce

1. Add print('PRINT build search widget autofocus=${widget.autofocus}'); on the first line of the SearchField build method (not SearchPage, both are in the same file) (I always put print in caps at the start so that I can search the logs for my print messages)

2. When then searching something you can see a lot of these messages, some with autofocus=true and a lot with autofocus=false

3. The autofocus=false even get printen further when navigating to the product page

4. The autofcous=false builds are from the search bar on the welcome card in the carussel, which is not supposed to be rebuilt here

Expected behavior

It should not rebuild.

Part of

• 🔍 Search (tracker) #991