Draft: [Patch] Reduce CTE repetition

[cpita-felix]

Refactoring macros/dataset.sql to reduce the number of references to the original activity stream CTE/ref passed into it. Should therefore reduce average runtime of the macro as CTE logic/disk reads are performed less frequently.

[cpita-felix]

going to close this PR. My intention was to rewrite dataset.sql as a series of direct left joins between activities, but I realized that that join could explode and generate spurious tuples, which would make it much slower to execute, and would require significant special case handling for the aggregate style relationships.