[FR] Pass header X-Gch-Request-Id to the user

[Felixoid]

Is your feature request related to a problem? Please describe. The graphite-clickhouse adds the header X-Gch-Request-Id to the answer, it will be useful to add it to the carbonapi answer too

Describe the solution you'd like carbonapi will pass all X-Gch-Request-Id to the user

[msaf1980]

What X-Gch-Request-Id will be passed for /render queries (2 requests - find and data with different request ids) ?

[Felixoid]

What X-Gch-Request-Id will be passed for /render queries (2 requests - find and data with different request ids) ?

I'd suggest to use comma separated values. Like X-Forwarded-For

[Felixoid]

Actually, separated find shouldn't be a case. Carbonapi must omit it and send pain render request with glob. But it will send different render requests per target, so the case itself is a 100% valid.