Tuples implementation

[romanzaycev]

Need to implement support for TVM Tuples

Need to write PHP classes that represent a TVM Tuple type in PHP. This is needed to make it easier to call get-methods of smartcontracts that accept Tuples as arguments.

Additional links:

• https://docs.ton.org/develop/func/types#tuples-types
• https://github.com/ton-core/ton-core/tree/main/src/tuple