Support re-encoding of indefinite length types.

[mesudip]

Why

Its important for my use-case that re-encoding some portion of decoded data creates the same binary.

What

When decoding indefinite length array, text, binary or map,

• return a proxy of the type
• retain the original segments so that it can be re-encoded to same data.
• when encoding, if a flag is set, use the indefinite length encoding.