Did Dht - add support for Jwa.ES256

[jiyoonie9]

when constructing dns packet from did dht toDnsPacket(), we need to be able to map keytype to a new JWA of ES256

and on the other hand when parsing dns packet into did dht fromDnsPacket(), we also need to implement Secp256r1 methods similar to what we have for Ed25519 and Secp256k1

relevant area of code
for toDnsPacket(): https://github.com/TBD54566975/web5-kt/blob/234-did-impl/dids/src/main/kotlin/web5/sdk/dids/methods/dht/DidDht.kt#L490-L494

for fromDnsPacket(): https://github.com/TBD54566975/web5-kt/blob/main/dids/src/main/kotlin/web5/sdk/dids/methods/dht/DidDht.kt#L589-L594