* updated ui for nft import button
* updated no nft image found in the center
* updated footer for all screens in tabs
* removed no nft state from nft tab
* updated snapshot
* lint fix
* fixed e2e tests
* fixed prep build error
* removed no nfts yet test
* updated tabs
* fixed prod error
* updated no nft screen
* changed button size to md
* Rename `provider` to `providerConfig`
The network controller `provider` state has been renamed to
`providerConfig`. This better reflects what this state is, and makes
this controller more closely aligned with the core network controller.
All references to the provider configuration have been updated to
prefer `providerConfig` over `provider`, to make the distinction clear
between a provider and provider config.
Closes#18902
* Add migration
