Fix the blob encoding type

[nazarhussain]

The blobs returned from the beacon-apis are the raw bytes not encoded into ssz.

Mentioning it as SSZ encoded cause confusion to decode the output from the API e.g. ssz.Blob.decode(api_response) which will not match with the actual blobs.

Some reference:

https://github.com/ChainSafe/lodestar/blob/ae984f0f6079f78c2445f36ae2ac09c9e868197e/packages/types/src/deneb/types.ts#L8

[nazarhussain]

@g11tech Please take a look at this small change.

[nflaig]

Mentioning it as SSZ encoded cause confusion to decode the output from the API e.g. ssz.Blob.decode(api_response) which will not match with the actual blobs.

What exactly are you trying to do? If you wanna decode the raw hex-encoded blob you can do ssz.Blob.fromJson()