feat(api): Support Parquet as a query response format.

[jeschkies]

What this PR does / why we need it:
This changes adds support for the header Accept: application/vnd.apacher.parquet. If this header is set the response for metric and stream queries will response with a Parquet file.

A metrics response has the columns timestamp, labels and value. A stream response has the columns timestamp, labels and line.

The Parquet file can be queried with e.g. DuckDB:

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
  • Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR

[chaudum]

LGTM

[chaudum]

LGTM Waiting for @JStickler for docs review.

[JStickler]

LGTM Waiting for @JStickler for docs review.

[docs team] docs updates LGTM