allow to treat B64 encodings as ASCII forgetting about B64 encoding

>>> let tstB64 = encodeAll . toEncoding () $ "Hello World" :: Enc '["enc-B64"] () B.ByteString
>>> displ (flattenAs tstB64 :: Enc '["r-ASCII"] () B.ByteString)
"MkEnc '[r-ASCII] () (ByteString SGVsbG8gV29ybGQ=)"

>>> let enc = toEncString @"r-IPv4" @T.Text tstIp
>>> fromEncString @IpV4 enc
IpV4F {oct1 = 128, oct2 = 1, oct3 = 1, oct4 = 10}

To get IpV4 out of the string we need to reverse previous reduce. This is currently done using helper splitPayload combinator.

>>> EnT.splitPayload @ '["r-Word8-decimal"] (T.splitOn $ T.pack ".") $ enc
[MkEnc Proxy () "128",MkEnc Proxy () "1",MkEnc Proxy () "1",MkEnc Proxy () "10"]

The conversion of a list to IpV4F needs handle errors but these errors are considered unexpected.

Note, again, the error condition exposed by this implementation could have been avoided if splitPayload returned fixed size Vect 4.

In this example toEncString converts IpV4 to Enc '["r-IPv4"] Text.

This is done with help of existing "r-Word8-decimal" annotation defined in Data.TypedEncoding.Instances.Restriction.Common

>>> toEncString @"r-IPv4" @T.Text tstIp
MkEnc Proxy () "128.1.1.10"

Implementation is a classic map reduce where reduce is done with help of foldEncStr

>>> let fn a b = if b == "" then a else a <> "." <> b
>>> let reduce = EnT.foldEncStr @'["r-IPv4"] @'["r-Word8-decimal"] () fn
>>> displ . reduce . fmap toEncString $ tstIp
"MkEnc '[r-IPv4] () 128.1.1.10"

Note lack of type safety here, the same code would work just fine if we added 5th field to IpV4F constructor.

Using something like a dependently typed

Vect 4 (Enc '["r-Word8-decimal"] () T.Text)

would have improved this situation. HList could be used for record types with heterogeneous fields.

Currently, 'type-encoding' library does not have these types in scope.