[feature]Make GreptimeDB as a grafana data source

[zqr10159]

Make greptime available as a grafana data source.

Checklist

• I have read the Contributing Guide
• I have written the necessary doc or comment.
• I have added the necessary unit tests and all cases have passed.

Add or update API

• I have added the necessary e2e tests and all cases have passed.

[github-actions]

license-eye has checked 3235 files.

Valid	Invalid	Ignored	Fixed
1649	1	1585	0

Click to see the invalid file list

• hertzbeat-collector/hertzbeat-collector-basic/src/main/java/org/apache/hertzbeat/collector/collect/prometheus/PrometheusCollect.java

Use this command to fix any missing license headers

```bash

docker run -it --rm -v $(pwd):/github/workspace apache/skywalking-eyes header fix

</details>

[tomsun28]

👍hi, what the different between PrometheusProxyCollectImpl and PrometheusAutoCollectImpl, can you share the design of this piece??

[zqr10159]

👍hi, what the different between PrometheusProxyCollectImpl and PrometheusAutoCollectImpl, can you share the design of this piece??

1. Auto Mode (PrometheusAutoCollectImpl)
   How it works:
   HertzBeat’s collector directly scrapes the Prometheus-compatible endpoints (such as node_exporter, blackbox_exporter, or custom Prometheus endpoints).
   Use case:
   Use this mode for standard Prometheus monitoring scenarios, where HertzBeat collects metrics directly from the target application or exporter.
   Mechanism:
   The collector parses the Prometheus metrics format and processes the data itself.
2. Proxy Mode (PrometheusProxyCollectImpl)
   How it works:
   HertzBeat acts as a proxy that forwards requests to a time-series database backend (like GreptimeDB or VictoriaMetrics) that supports the Prometheus API. Instead of scraping exporters directly, it queries historical or real-time metrics from the database via API.
   Use case:
   Use this mode when integrating with large-scale metric storage (such as GreptimeDB or VictoriaMetrics). It's especially useful if you want to use HertzBeat as a unified data source for Grafana dashboards, querying through the database rather than directly from exporters.
   Mechanism:
   HertzBeat does not parse/export data itself, but relays requests and responses between Grafana (or another client) and the backend database.

Currently, the proxy code is marked as todo because for the current architecture, although proxy can reduce the load on hertzbeat, direct forwarding to the database makes alerting impossible. I'm sure he'll be useful as a future feature for lossless collection of metrics!

[tomsun28]

LGTM