* 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
* Deprecating Rinkeby, setting default debug network to Goerli
* Deprecating Ropsten and Kovan
* Conflict fix
* Remove unused localization, test fixes
* Add migration for moving used deprecated testnets to custom networks
* Fix migrator test
* Add more unit tests
* Migration updates provider type to rpc if deprecated network is selected
* Migration fully and correctly updates the provider if selected network is a deprecated testnet
* Continue to show deprecation warning on each of rinkeby, ropsten and kovan
* Add rpcUrl deprecation message to loading screen
* Removing mayBeFauceting prop
Co-authored-by: Dan Miller <danjm.com@gmail.com>