Implement Requirements SCH3003 and SCH3003.1

[ArielSAdamsNASA]

Checklist (Please check before submitting)

• I reviewed the Contributing Guide.
• I performed a cursory search to see if the bug report is relevant, not redundant, nor in conflict with other tickets.

Is your feature request related to a problem? Please describe.
Requirements SCH3003 and SCH3003.1 are not implemented.

Describe the solution you'd like
SCH3003: SCH shall allow the user to combine one or more groups of activities in the Schedule Definition Table into one or more Multi-Groups.
SCH3003.1: SCH shall support a maximum of 24 Multi-Groups.

Additional context
Should be implemented by SCH_EnableGroupCmd in sch_cmds.c. This allows a group to be enabled, but does not allow users to combine groups. Groups are also not limited.

Reporter Info
Ariel Adams, MCSG Tech