change format of blobbers keys

[boddumanohar]

At the moment, the blobber keys has the following format:

https://github.com/0chain/blobber/blob/staging/docker.local/keys_config/b0bnode1_keys.txt#L1C1-L2

where the first line is public key
and the second line is private key

and we internally convert public to wallet ID.

Due to this keys format, it has become a little tedious to faucet tokens on the blobber wallet. Because blobber will have to go through the steps described here:
https://0chain.slack.com/archives/C03788G8N2D/p1683202995153189?thread_ts=1683111428.140489&cid=C03788G8N2D

Instead of going through this, we could change the keys format of the blobbers. We could change the keys format to wallet.json format.