Log SQL error message

[OskarsPakers]

Description

When metric scrape fails, instead of SQL error only "unsupported value type" is logged.

Fixes #343

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Started locally with custom-metrics.toml which includes sql query that produces error

Screenshots (if appropriate):

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• [N/A] I have commented my code, particularly in hard-to-understand areas
• [N/A] I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• Updated version in Makefile respecting semver v2

[Yannig]

Thanks for this contribution ! :)