The go-gost fork of go-shadowsocks2 dropped built-in support for the
none/dummy cipher that was present in the original go-shadowsocks2.
Combined with the SS components' hard requirement for auth (and
therefore a valid cipher), this made gost fail to start with
method=none or method=dummy.
Add a no-op cipher in x/internal/util/ss/none/ that implements the
core.ShadowCipher interface using the standard go-shadowsocks2 AEAD
framing (salt + length-prefixed chunks, target address embedding)
without actual encryption. SaltSize=16 ensures random salts on every
connection to avoid bloom-ring replay detection.
Update SS TCP connector/handler and SS UDP connector/handler to detect
method=none/dummy (case-insensitive) and use the no-op cipher instead
of utils.NewClientConfig/NewServerConfig.
Fixesgo-gost/x#105
ginuerzh