Add a new API for exporting data as a CSV

[Hayk Davtyan]

Is your feature request related to a problem? Please describe.
Add a new API that allows users to export data as a CSV file based on their Prometheus queries.

Describe the solution you'd like
This API should use the native Prometheus API /api/v1/query.

Describe alternatives you've considered
N/A

Additional context
N/A