OrderGroupAttribute implementation

OrderGroups will also be extended via attributes to associate cycle number, the total number of cycles in the regimen, and the length of the regimen cycles.

Please refer to this Talk post for more detail: https://talk.openmrs.org/t/chemotherapy-ordering-data-design/19133

Copy changes in these commits:

https://github.com/idlewis/openmrs-core/commit/db8cdd1b57c38a6da8d90bfb6e05a2a08637ef85

https://github.com/idlewis/openmrs-core/commit/278c4cd74f1f4863726c012cea8994588bd88f3e

https://github.com/idlewis/openmrs-core/commit/900bc37f0fb608ff0b251e013a17ff285025f6ac

https://github.com/idlewis/openmrs-core/commit/31ddd1a36cb60636da84b7e4073cd96a339c6363

https://github.com/idlewis/openmrs-core/commit/684c5ad82ef5776c73b90f01d0279fa5c664f401