[query] Use SourcePos for implicit timing context

[ehigham]

Change Description

Fixes #<issue_number> (delete if N/A)

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Security Assessment

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[ehigham]

• [query] Use SourcePos for implicit timing context #14732 👈 (View in Graphite)
• [query] Lowering + Optimisation with implict timing context #14731 : 2 other dependent PRs (#14748 , #14952 )
• [query] Lift backend state into (Batch|Py4J)QueryDriver #14698
• main

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