* feat: improve prove_finality api and export it
* fmt
* fix
* improve prove_finality and kept private
* Update client/finality-grandpa/src/finality_proof.rs
Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>
* add `prove_finality_proof` to `FinalityProofProvider`
* fix some and impl Clone for FinalityProofProvider
* improve by suggestions
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Co-authored-by: André Silva <123550+andresilva@users.noreply.github.com>