add intial benchmarks

[AliBasicCoder]

add benchmarks

you can run benchmarks via

cargo bench --features value

debugging issue #7

[AliBasicCoder]

i generated the json via json-generator.com not with code so i included it
you can removed it and choose some library to generate the json

[AliBasicCoder]

i manged to fix the panic unexpected end of stream in collect_chunks test
unfortunately the issue #7 still remains

[AliBasicCoder]

after looking into the code i think this problem is cause by the constant modification of the buffer in the decoder all over the deserialization code like in methods buffer and buffer_string

unfortunately if this is the case, a lot of the deserialization code will need to be modified
also i suspect that this causes performance to suffer considering that at the best case destream_json does this task in around 400ms while serde_json does it in around 80ms (around 5x faster)

[haydnv]

Hi Ali, sorry I missed this! Your analysis is super helpful. Can you please remove the generated.json file from the commit?