Move EngineContext outside of the engine package

[dmjb]

This avoids a circular dependency when importing the flags package into engine

Summary

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Fixes #(related issue)

Change Type

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• Bug fix (resolves an issue without affecting existing features)
• Feature (adds new functionality without breaking changes)
• Breaking change (may impact existing functionalities or require documentation updates)
• Documentation (updates or additions to documentation)
• Refactoring or test improvements (no bug fixes or new functionality)

Testing

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Review Checklist:

• Reviewed my own code for quality and clarity.
• Added comments to complex or tricky code sections.
• Updated any affected documentation.
• Included tests that validate the fix or feature.
• Checked that related changes are merged.

[coveralls]

coverage: 52.741% (+0.005%) from 52.736%
when pulling 2393141 on move-enginecontext-struct
into ef45f63 on main.

[coveralls]

coverage: 52.741% (+0.005%) from 52.736%
when pulling bac65f3 on move-enginecontext-struct
into ef45f63 on main.

[coveralls]

coverage: 52.736%. remained the same
when pulling bac65f3 on move-enginecontext-struct
into ef45f63 on main.

[coveralls]

coverage: 52.736%. remained the same
when pulling bac65f3 on move-enginecontext-struct
into ef45f63 on main.

[coveralls]

coverage: 52.736%. remained the same
when pulling bac65f3 on move-enginecontext-struct
into ef45f63 on main.

[coveralls]

coverage: 52.736%. remained the same
when pulling bac65f3 on move-enginecontext-struct
into ef45f63 on main.