* Implemented `seal_ecdsa_recovery` function in the contract pallet.
Added benchmark and unit test.

* Run `cargo fmt`

* Skip fmt for slices

* Changes according comments in pull request.

* Fix build without `unstable-interface` feature

* Applied suggestion from the review

* Apply suggestions from code review

Co-authored-by: Alexander Theißen <alex.theissen@me.com>

* Apply suggestions from code review

Co-authored-by: Alexander Theißen <alex.theissen@me.com>

* Changed RecoveryFailed to EcdsaRecoverFailed

* Manually updated weights.rs

* Apply suggestions from code review

Co-authored-by: Michael Müller <mich@elmueller.net>

Co-authored-by: Alexander Theißen <alex.theissen@me.com>
Co-authored-by: Michael Müller <mich@elmueller.net>