Better buffer handler to TCP data

[zenaro147]

Some games can stream too many data that Pico probably can't handle it, (for example, Pokemon News on Crystal)

Maybe some kind of "dynamic buffer handler" using pointers can do the job

[zenaro147]

Improved into this commit https://github.com/zenaro147/PicoAdapterGB/commit/6256ea58a4d4afecf43ca27f90b0cf4968c7c48c