Add axuiliary serialize function

[Juan-M-V]

Make Program serializable into a json string

Description

The aim of this PR is to make Program serializable. That way it can be converted to a json object. This is achieved by converting Program into a ProgramJson through the _program_to_json function.
Currently missing a conversion between hints for Program and ProgramJson

Checklist

• Linked to Github Issue
• Unit tests added
• Integration tests added.
• This change requires new documentation.
  • Documentation has been added/updated.
  • CHANGELOG has been updated.

[github-actions]

Benchmark Results for unmodified programs 🚀

Command	Mean [s]	Min [s]	Max [s]	Relative
base big_factorial	4.718 ± 0.046	4.671	4.844	1.00
head big_factorial	4.766 ± 0.023	4.734	4.804	1.01 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base big_fibonacci	3.943 ± 0.041	3.904	4.034	1.00
head big_fibonacci	3.980 ± 0.023	3.939	4.011	1.01 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base blake2s_integration_benchmark	11.049 ± 0.077	10.916	11.169	1.00
head blake2s_integration_benchmark	11.148 ± 0.197	11.014	11.648	1.01 ± 0.02

Command	Mean [s]	Min [s]	Max [s]	Relative
base compare_arrays_200000	4.023 ± 0.025	3.995	4.072	1.00
head compare_arrays_200000	4.070 ± 0.062	4.033	4.240	1.01 ± 0.02

Command	Mean [s]	Min [s]	Max [s]	Relative
base dict_integration_benchmark	2.676 ± 0.012	2.660	2.692	1.00
head dict_integration_benchmark	2.710 ± 0.010	2.701	2.733	1.01 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base field_arithmetic_get_square_benchmark	2.008 ± 0.016	1.994	2.049	1.00
head field_arithmetic_get_square_benchmark	2.043 ± 0.042	2.007	2.116	1.02 ± 0.02

Command	Mean [s]	Min [s]	Max [s]	Relative
base integration_builtins	11.005 ± 0.101	10.917	11.259	1.00 ± 0.01
head integration_builtins	10.997 ± 0.016	10.974	11.023	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base keccak_integration_benchmark	11.229 ± 0.018	11.205	11.256	1.00
head keccak_integration_benchmark	11.296 ± 0.069	11.161	11.375	1.01 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base linear_search	4.009 ± 0.012	3.992	4.030	1.00
head linear_search	4.109 ± 0.135	4.019	4.376	1.02 ± 0.03

Command	Mean [s]	Min [s]	Max [s]	Relative
base math_cmp_and_pow_integration_benchmark	2.901 ± 0.025	2.869	2.961	1.00
head math_cmp_and_pow_integration_benchmark	2.945 ± 0.045	2.916	3.068	1.02 ± 0.02

Command	Mean [s]	Min [s]	Max [s]	Relative
base math_integration_benchmark	2.635 ± 0.006	2.626	2.645	1.00
head math_integration_benchmark	2.664 ± 0.012	2.645	2.691	1.01 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base memory_integration_benchmark	2.321 ± 0.006	2.314	2.331	1.00
head memory_integration_benchmark	2.341 ± 0.003	2.337	2.348	1.01 ± 0.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base operations_with_data_structures_benchmarks	2.583 ± 0.044	2.554	2.679	1.00
head operations_with_data_structures_benchmarks	2.602 ± 0.008	2.591	2.616	1.01 ± 0.02

Command	Mean [ms]	Min [ms]	Max [ms]	Relative
base pedersen	937.5 ± 5.2	932.0	950.5	1.00
head pedersen	959.6 ± 25.8	938.6	1005.4	1.02 ± 0.03

Command	Mean [s]	Min [s]	Max [s]	Relative
base poseidon_integration_benchmark	1.746 ± 0.005	1.740	1.754	1.01 ± 0.01
head poseidon_integration_benchmark	1.737 ± 0.010	1.730	1.764	1.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base secp_integration_benchmark	3.330 ± 0.017	3.317	3.374	1.00
head secp_integration_benchmark	3.361 ± 0.008	3.352	3.372	1.01 ± 0.01

Command	Mean [s]	Min [s]	Max [s]	Relative
base set_integration_benchmark	1.939 ± 0.005	1.934	1.951	1.00
head set_integration_benchmark	2.000 ± 0.006	1.995	2.014	1.03 ± 0.00

Command	Mean [s]	Min [s]	Max [s]	Relative
base uint256_integration_benchmark	7.219 ± 0.013	7.201	7.242	1.00
head uint256_integration_benchmark	7.292 ± 0.097	7.238	7.564	1.01 ± 0.01

[pefontana]

Done here #1458