Decode decodes a byte array to provide an interface like `base64/DecodeString`.

DecodeGunzip base64 decodes a string with optional gzip uncompression.

DecodeGunzipJSON base64 decodes a string with optoinal gunzip uncompression and then unmarshals the data to a struct.

Encode with optional gzip compression.

EncodeGzipJSON encodes a struct that is JSON encoded.

ReadAll provides an interface like `io.ReadAll` with optional base64 decoding.

RxCheckMore is from https://stackoverflow.com/a/8571649/1908967.