Make build outliers SP support dynamic entity types

[Jongmassey]

This refactoring is motivated by the need to report on outliers for the entities in the new NHS primary care organisational structure.

builds table now has an entities array column which lists which entity types (e.g. ICB, PCN, STP, CCG) were used in the build of that dataset.

The build_outliers_dynamic sp now requires this entities array as a parameter and operates over it to generate the required dynamic sql statements throughout.

In order to present a consistent schema to the tables used in this dynamic sql, a per-entity-type view is created for each mapping the practice id (at which the primary level of aggregation is performed and stored in the summed table) to the id of the parent entity in question.