[Feature] Support custom document emitter

[BGMSound]

• Refactor package structure
• Separate the responsibility of validating document test results from the emitter
• Support custom document emitter

[github-actions]

Test Results

17 tests   17 ✅  13s ⏱️
 9 suites   0 💤
 9 files     0 ❌

Results for commit f46f695.

[github-actions]

Code Coverage Report

Overall Project	37.3% -8.77%	🍏
Files changed	40.94%	🍏

Module	Coverage
Kover Gradle Plugin XML report for :documentify-sample:reactive-sample	100%	🍏
Kover Gradle Plugin XML report for :	70.75% -2.78%	🍏
Kover Gradle Plugin XML report for :documentify-project:documentify-core	0.54% -6.74%	❌
Kover Gradle Plugin XML report for :documentify-project:documentify-mvc	0.45% -30.09%	❌
Kover Gradle Plugin XML report for :documentify-project:documentify-reactive	0.43% -28.33%	❌

Files

Module	File	Coverage
Kover Gradle Plugin XML report for :documentify-sample:reactive-sample	SampleController.kt	100%	🍏
Kover Gradle Plugin XML report for :	EmitterFactory.kt	100%	🍏
	AbstractMvcDocumentEmitter.kt	100%	🍏
	AbstractDocumentEmitter.kt	100%	🍏
	JsonResultMatcher.kt	100%	🍏
	EmitterFactory.kt	100%	🍏
	AbstractReactiveDocumentEmitter.kt	100%	🍏
	WebTestClientReactiveDocumentEmitter.kt	97.31%	🍏
	RestAssuredMvcDocumentEmitter.kt	96.82%	🍏
	AbstractDocumentResult.kt	95.76% -4.24%	🍏
	StandaloneReactiveContextEnvironment.kt	89.19%	🍏
	StandaloneMvcContextEnvironment.kt	82.14%	🍏
	DefaultDocumentSpecSampleAggregator.kt	78.18%	🍏
	AlternativeMvcResponseDocumentController.kt	67.57% -32.43%	🍏
	MvcDocumentResult.kt	65.05% -34.95%	🍏
	Documentify.kt	61.39% -16.83%	🍏
	Documentify.kt	61.17% -17.48%	🍏
	ReactiveDocumentResult.kt	47.67% -52.33%	🍏
	AbstractStandaloneContextEnvironment.kt	43.16%	🍏
	ValidatableMockMvcResponseAdapter.kt	40%	🍏
	StandaloneContextEnvironment.kt	0%	🍏
Kover Gradle Plugin XML report for :documentify-project:documentify-core	AbstractDocumentEmitter.kt	0% -12.82%	❌
	AbstractDocumentResult.kt	0%	❌
	DefaultDocumentSpecSampleAggregator.kt	0% -41.82%	❌
	JsonResultMatcher.kt	0%	❌
	StandaloneContextEnvironment.kt	0%	🍏
	AbstractStandaloneContextEnvironment.kt	0% -8.42%	❌
Kover Gradle Plugin XML report for :documentify-project:documentify-mvc	RestAssuredMvcDocumentEmitter.kt	0.98% -15.65%	❌
	StandaloneMvcContextEnvironment.kt	0% -11.61%	❌
	EmitterFactory.kt	0%	🍏
	MvcDocumentResult.kt	0%	❌
	AlternativeMvcResponseDocumentController.kt	0% -78.38%	❌
	AbstractMvcDocumentEmitter.kt	0% -57.14%	❌
	ValidatableMockMvcResponseAdapter.kt	0%	🍏
	Documentify.kt	0% -44.55%	❌
Kover Gradle Plugin XML report for :documentify-project:documentify-reactive	WebTestClientReactiveDocumentEmitter.kt	0.98% -27.63%	❌
	Documentify.kt	0% -44.66%	❌
	ReactiveDocumentResult.kt	0%	❌
	EmitterFactory.kt	0%	🍏
	AbstractReactiveDocumentEmitter.kt	0% -16.67%	❌
	StandaloneReactiveContextEnvironment.kt	0% -7.57%	❌