Combine EcdsaSecp256k1VerificationProvider and Ed25519VerificationProvider

[swirlds-automation]

• Now that Bouncy Castle is used for both types of verification, the separate classes EcdsaSecp256k1VerificationProvider and Ed25519VerificationProvider can be combined
• Remove Ecdsasecp256k1Verifier and Ed25519Verifier, as they will no longer be necessary

related to https://github.com/swirlds/swirlds-platform/issues/5261

[swirlds-automation]

_{migrated from:
url=https://github.com/swirlds/swirlds-platform/issues/5322
author:alittley, #:5322, createdAt:2022-05-10T15:19:45Z, updatedAt=2023-02-17T21:50:10Z
labels=Feature Enhancement,Migration:Base}