New kymastats receiver

[a-thaler]

Description
As part of kyma-project/telemetry-manager#728 a receiver is needed which can collect metrics about all Kyma module states and conditions. A concrete proposal can be found here: https://github.com/kyma-project/telemetry-manager/blob/main/docs/contributor/arch/011-kymastatsmetrics.md

As a first step, create a receiver which collects the metrics for a hardcoded receiver

Criterias

• Have the new receiver buildable
• The receiver can be configured with the typical auth config (see https://github.com/kyma-project/telemetry-manager/blob/main/docs/contributor/arch/011-kymastatsmetrics.md)
• Have a readme comparable to the upstream readme's, summarizing the API and usage pattern
• The receiver will always emit the metrics for the hardcoded telemetry module (assumption is that it is present always)
• Have unit tests assuring that emitted metrics are reflecting current module status

Reasons

Attachments

[hisarbalik]

Receiver kymastats emit two metrics

• kyma.module.status.state, emit status->state for each state value with a value 1, contains metric attribute state as the value of status->state attribute
• kyma.module.status.conditions, emit status->conditions attribute when module provides it, the metric value depends on condition status attribute and has following values: "True" -> 1, "False" -> 0, and -1 for other values

The receiver by default will scrape only Kyma Telemetry module.

All the available metrics, metric attributes, and configuration parameters are documented.