[FEATURE] Cluster config API should provide meaningful status instead of a bitmap encoded numeric value

[kkhatua]

Is your feature request related to a problem?
When checking cluster state of Performance Analyzer, the responses are bit-encoded numeric values, which don't provide much meaningful insight.

GET localhost:9200/_plugins/_performanceanalyzer/cluster/config
{"batchMetricsRetentionPeriodMinutes": 7, "currentPerformanceAnalyzerClusterState": 19, "shardsPerCollection": 0}

The value of 19 translates to 0b1011, which in turn provides the following being enabled:

1. PerformanceAnalyzer : Enabled (LSB)
2. RCA Engine : Enabled
3. Logging : Disabled
4. BatchMetrics : Enabled
5. ThreadContentionMonitoring : Disabled (MSB)

What solution would you like?
The response should be meaningful like:

GET localhost:9200/_plugins/_performanceanalyzer/cluster/config
{
	"batchMetricsRetentionPeriodMinutes": 7,
	"currentPerformanceAnalyzerClusterState": {
		"PerformanceAnalyzer": "enabled",
		"Rca": "enabled",
		"Logging": "enabled",
		"BatchMetrics": "enabled",
		"ThreadContentionMonitoring": "enabled"
	},
	"shardsPerCollection": 0
}

What alternatives have you considered?
None

Do you have any additional context?
None