[Feature] Make it easier to instantiate a `RootProvider`

[onbjerg]

Component

providers, pubsub

Describe the feature you would like

There should be an easy way to instantiate a RootProvider for any given transport, currently we do:

RootProvider::<Network, _>::new(RpcClient:new(transport, true))

where the transport itself can also be "complex" to instantiate

#190 (comment)

Additional context

No response

[onbjerg]

Closing in favor of #318