Port code to AssemblyScript

Port a binary tuple packing/unpacking module into efficient AssemblyScript.

This module has already been ported to many different languages.

TypeScript version should be the easiest one to port.

TypeScript version: https://github.com/josephg/fdb-tuple

Expected result: efficient WebAssembly module, that packs and unpacks identically to the TypeScript module.


Same module in other languages, only for reference:
Python: https://github.com/apple/foundationdb/blob/main/bindings/python/fdb/tuple.py
Cpp: https://github.com/apple/foundationdb/blob/main/bindings/flow/Tuple.cpp
Go: https://github.com/apple/foundationdb/blob/main/bindings/go/src/fdb/tuple/tuple.go
Ruby: https://github.com/apple/foundationdb/blob/main/bindings/ruby/lib/fdbtuple.rb

Format specifications can be found here: https://github.com/apple/foundationdb/blob/main/design/tuple.md