When running scarb test or scarb cairo-test with the --json flag, the test output should be in JSON format

[0xNeshi]

Problem

The --json flag should result in all output being in JSON format. This would be extremely helpful when creating a Test Runner for the Cairo track on Exercism.

Currently this flag does virtually nothing to format the test output:

• scarb --json cairo-test --include-ignored just prints everything in multiple lines:
  
• scarb --json test --include-ignored prints the current operation as JSON, and then prints the actual test output the same as before:
  

Proposed Solution

The output for the tests should be in JSON format, something like:

{"status":"compiling","message":"test(leap_unittest) leap v0.1.0 (/home/nenad/repos/work/cairo-test-runner/tests/partial-fail/Scarb.toml)"}
{"status":"compiling","message":"test(leap_leap) leap_leap v0.1.0 (/home/nenad/repos/work/cairo-test-runner/tests/partial-fail/Scarb.toml)"}
{"status":"finished","message":"release target(s) in 2 seconds"}
{"status":"running","message":"cairo-test leap"}
{"status":"running","message":"9 tests"}
{"status":"ok","test":"leap_leap::leap::year_not_divisible_by_4_in_common_year", "gas_usage_est": 46040}
{"status":"ok","test":"leap_leap::leap::year_divisible_by_400_but_not_by_125_is_still_a_leap_year", "gas_usage_est": 45840}
{"status":"fail","test":"leap_leap::leap::year_divisible_by_200_not_divisible_by_400_in_common_year", "gas_usage_est": 50580}
{"status":"fail","test":"leap_leap::leap::year_divisible_by_100_not_divisible_by_400_in_common_year", "gas_usage_est": 50580}
{"status":"ok","test":"leap_leap::leap::year_divisible_by_400_is_leap_year", "gas_usage_est": 45840}
{"status":"ok","test":"leap_leap::leap::year_divisible_by_4_not_divisible_by_100_in_leap_year", "gas_usage_est": 45840}
{"status":"ok","test":"leap_leap::leap::year_divisible_by_2_not_divisible_by_4_in_common_year", "gas_usage_est": 46040}
{"status":"ok","test":"leap_leap::leap::year_divisible_by_4_and_5_is_still_a_leap_year", "gas_usage_est": 45840}
{"status":"fail","test":"leap_leap::leap::year_divisible_by_100_but_not_by_3_is_still_not_a_leap_year", "gas_usage_est": 50580}
{"status":"finished", "failures": [
    {"test": "leap_leap::leap::year_divisible_by_200_not_divisible_by_400_in_common_year", "message": "Panicked with \"assertion failed: `!is_leap_year(1800)`.\""},
    {"test": "leap_leap::leap::year_divisible_by_100_not_divisible_by_400_in_common_year", "message": "Panicked with \"assertion failed: `!is_leap_year(2100)`.\""},
    {"test": "leap_leap::leap::year_divisible_by_100_but_not_by_3_is_still_not_a_leap_year", "message": "Panicked with \"assertion failed: `!is_leap_year(1900)`.\""},
]}
{"status":"finished", "message":"Error: test result: FAILED. 6 passed; 3 failed; 0 ignored"}

Notes

No response