Add support for affine indirect copies in Realm

This change introduces support for affine indirect copies in Realm that handles all generic affine transform in the form A*x + b. The change is supplied with a text file which defines copy events used for testing. A single copy event is executed separately for gather and scatter. The provided test cases are covering translation, scaling, transpose, reflection, shearing and some of the combined transforms. Dense multi-piece instances are covered by the tests as well.

The change does not support data distributed across multiple instances (yet).

Testing done: <CI: https://gitlab.com/StanfordLegion/legion/-/pipelines/492188040>