Update ABS time quarters

[ardimirzaei]

The ABS data shows the end for the end of the quarter, but pandas auto defaults to the begin of the quarter, Added and offset to the end of the quarter

Summary

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Checklist

• [ ] The change is tested and works locally.
• [ ] All related issues are referenced.
• [ ] Blog post included in PR if required e.g. new feature.

[ardimirzaei]

@sjtrny noting that I've applied the offset globally to the ABS data, but this PR needs a double check that the all ABS data refers to the end of the quarter.

[sjtrny]

This'll do for now, but we should specify the transformation at the series level in the JSON file in future.