ci: add quick-check with rustfmt (#615)

* ci: add quick-check with clippy and rustfmt

* chore: rustfmt round

* chore: set the same rustfmt config than substrate

* chore: fix formatting

* cI: remove clippy

* ci: switch to nightly for the checks

* ci: fix toolchains and naming

* ci: Limit the check to formatting

* chore: fix formatting

* Update .rustfmt.toml

* Update .rustfmt.toml

Co-authored-by: Bastian Köcher <[email protected]>