* Do not call `initialize_block` before any runtime api
Before this change we always called `initialize_block` before calling
into the runtime. There was already support with `skip_initialize` to skip
the initialization. Almost no runtime_api requires that
`initialize_block` is called before. Actually this only leads to higher
execution times most of the time, because all runtime modules are
initialized and this is especially expensive when the block contained a
runtime upgrade.
TLDR: Do not call `initialize_block` before calling a runtime api.
* Change `validate_transaction` interface
* Fix rpc test
* Fixes and comments
* Some docs
Bastian Köcher
d489bd70b5