Adding table name to remove ambiguity from group by statement

[eiffel777]

This fixes the following error seen in the metrics-dev logs.

2020-02-12 04:19:05 [warning] SQL warnings on table '`modw_cloud`.`instance`' generated by action xdmod.jobs-cloud-extract-generic.GenericCloudInstanceIngestor
2020-02-12 04:19:05 [warning] Warning 1052 Column 'service_provider' in group statement is ambiguous

Tests performed

Ran in docker and manually tested

Types of changes

• 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 change)

Checklist:

• My code follows the code style of this project as found in the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

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0 Vulnerabilities (and 0 Security Hotspots to review)
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