First in a series of PRs that reduces our use of sp-std with a view to deprecating it. This is just looking at /substrate and moving some of the references from `sp-std` to `core`. These particular changes should be uncontroversial. Where macros are used `::core` should be used to remove any ambiguity. part of https://github.com/paritytech/polkadot-sdk/issues/2101
Substrate runtime api
The Substrate runtime api is the crucial interface between the node and the runtime.
Every call that goes into the runtime is done with a runtime api. The runtime apis are not fixed.
Every Substrate user can define its own apis with
decl_runtime_apis and implement them in
the runtime with impl_runtime_apis.
Every Substrate runtime needs to implement the [Core] runtime api. This api provides the basic
functionality that every runtime needs to export.
Besides the macros and the [Core] runtime api, this crates provides the [Metadata] runtime
api, the [ApiExt] trait, the [CallApiAt] trait and the [ConstructRuntimeApi] trait.
On a meta level this implies, the client calls the generated API from the client perspective.
License: Apache-2.0