Draft: Benchmark CI Header validation

What does this MR do and why?

This MR benchmarks the validation speed of the CI Header when using Ruby classes vs using a JSON schema.

Issue: #467375 (closed)

Benchmarking (times in milliseconds)

1. JSON schema is loaded for every run - benchmark_json_schema_no_preload.rb

• JsonSchemaValidator loads the schema for every validation it performs. This benchmark tests that method
• Ruby validation is faster in the majority of runs

Validation method	Number of runs	user (ms)	system (ms)	total (ms)	real (ms)
Ruby	1	0.667	0.067	0.734	(0.727)
JSON schema	1	0.400	0.158	0.558	(0.559)
Ruby	5	0.774	0.010	0.784	(0.784)
JSON schema	5	0.903	0.170	1.073	(1.074)
Ruby	50	7.195	0.067	7.262	(7.262)
JSON schema	50	8.398	1.799	10.197	(10.199)
Ruby	500	72.926	1.159	74.085	(74.085)
JSON schema	500	79.843	17.520	97.363	(97.371)

2. JSON schema is preloaded and reused between runs - benchmark_json_schema_preload.rb

• By preloading the JSON schema, we greatly reduce the JSON schema validation time
• JSON schema validation is now consistently 3 - 4x faster than Ruby validation

Validation method	Number of runs	user (ms)	system (ms)	total (ms)	real (ms)
Ruby	1	0.174	0.003	0.177	(0.176)
JSON schema	1	0.060	0.002	0.062	(0.061)
Ruby	5	0.866	0.068	0.934	(0.934)
JSON schema	5	0.236	0.008	0.244	(0.245)
Ruby	50	7.941	0.601	8.542	(8.544)
JSON schema	50	2.379	0.104	2.483	(2.487)
Ruby	500	72.788	1.734	74.522	(74.525)
JSON schema	500	23.779	0.646	24.425	(24.429)