* Add ecdsa support to signer
* Remove nix. Cleanup.
* remove ecdsa example and small tidy
* fmt
* fix wasm test
* feature flag ecdsa/sr25519 support, use global signing context
* clippy fix
* ensure signers all impl Signer trait in doc test
* fix CI
* fix digner test
* remove dead code warnings when no features enabled
* move dead code attr to right place
* fix random clippy error that popped up
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Co-authored-by: Lech Głowiak <lech.glowiak@gmail.com>