Refactor Exo Rego Code (#662)

* first round of cleanup

first round of cleanup

* create helper funtion for conditions filter code

create helper funtion for conditions filter code

* add comments pt 1

add comments pt 1

add comments pt 2

add comments pt 2

* update syntax for constant

update syntax for constant

* update for test package

update for test package

* fix policy indicated comments

fix policy indicated comments

* fix json formatting & rego formatting

fix json formatting & rego formatting

* refactor out duplicate code in tests

refactor out duplicate code in tests

* remove unused imports

remove unused imports

* remove unused var

remove unused var

* remove constant