[ecdsa] name recoverPubkey -> recoverPubkeyFromDigest for variant

Given that we generate a C API from the code, we need to differentiate
the function names for the types. The default takes a message and this
variant takes a digest (as used in Ethereum's precompile for ECRecover).

Author: Vindaar

constantine/eth_ecdsa_signatures.nim

@@ -79,7 +79,7 @@ proc recoverPubkey*(
   ## even `y` coordinate of the `R` point.
   publicKey.raw.recoverPubkey(signature, message, evenY, keccak256)
 
-proc recoverPubkey*(
+proc recoverPubkeyFromDigest*(
     publicKey: var PublicKey,
     msgHash: Fr[Secp256k1],
     signature: Signature,

constantine/ethereum_evm_precompiles.nim

@@ -1340,7 +1340,7 @@ func eth_evm_ecrecover*(r: var openArray[byte],
 
   # 4. perform pubkey recovery
   var pubKey {.noinit.}: PublicKey
-  pubKey.recoverPubkey(msgHash, signature, evenY) # , keccak256)
+  pubKey.recoverPubkeyFromDigest(msgHash, signature, evenY)
 
   # 4. now calculate the Ethereum address of the public key (keccak256)
   privateAccess(PublicKey)