* 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
* Fix incorrect balance in signature request header
* Fix unit tests
* Fix tests and increase unit test coverage
* actually fix unit tests
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Co-authored-by: Dan Miller <danjm.com@gmail.com>
