* WIP new Metadata type
* Finish basic Metadata impl inc hashing and validation
* remove caching from metadata; can add that higher up
* remove caches
* update retain to use Metadata
* clippy fixes
* update codegen to use Metadata
* clippy
* WIP fixing subxt lib
* WIP fixing tests, rebuild artifacts, fix OrderedMap::retain
* get --all-targets compiling
* move DispatchError type lookup back to being optional
* cargo clippy
* fix docs
* re-use VariantIndex to get variants
* add docs and enforce docs on metadata crate
* fix docs
* add test and fix docs
* cargo fmt
* address review comments
* update lockfiles
* ExactSizeIter so we can ask for len() of things (and hopefully soon is_empty()
* Move all deps to workspace toml
* cargo fmt and codec 3.4, removing now unneeded 'full' feature
* add wasm-tests to workspace and fix subxt inheritng
* cargo fmt
* wasm-test thing can't be in workspace so revert that
* remove unwanted target dir from wasm-tests
James Wilson