[SL-3384] [Feature] Add a --sql option to MF queries

[siljamardla]

Is this your first time submitting a feature request?

• I have read the expectations for open source contributors
• I have searched the existing issues, and I could not find an existing issue for this feature
• I am requesting a straightforward extension of existing metricflow functionality, rather than a Big Idea better suited to a discussion

Describe the feature

There's an option to write the outcome of a MetricFlow query to csv, something like this:

mf query --saved-query my_saved_query --csv tmp_my_saved_query_output.csv

The output file is pure CSV, no ⠋ Initiating query… stuff in the beginning.

Similarly, I'd like to output the --explain version of the query to a separate file, pure SQL, no ⠋ Initiating query… stuff.

mf query --saved-query my_saved_query --explain --sql tmp_my_saved_query_output.sql

Describe alternatives you've considered

At the moment, my only option is to push the command output to a file, something like this:

mf query --saved-query my_saved_query --csv tmp_my_saved_query_output.csv

which prints everything to the file, including the ⠋ Initiating query… stuff that I then need to clean up from the file (#1555). The longer the query takes the more lines of ⠋ Initiating query… I get in the output. In some cases, this is thousands of lines (I just recently timed a saved query of 80 metrics, it took 4m10s).

Who will this benefit?

Everyone

_SL-3384

[plypaul]

Currently thinking that a common --quiet flag would be most appropriate. Is this for a scripting use case?