Fix #108, dispatch pattern for SC

[jphickey]

Checklist (Please check before submitting)

• [x] I reviewed the Contributing Guide.
• [x] I signed and emailed the appropriate Contributor License Agreement to GSFC-SoftwareRelease@mail.nasa.gov and copied cfs-program@lists.nasa.gov.

Describe the contribution Move switch statements to a separate dispatch source file, and update all unit tests accordingly.

All business logic of commands is put into separate command handler functions in sc_cmds.c. No logic is inside the switch statement, outside of message validation.

Fixes #108

Testing performed Build and run SC and all tests

Expected behavior changes No external/observable behavior change

System(s) tested on Debian

Additional context Intent is to improve code consistency, ease future maintenance, and to match patterns used elsewhere.

Contributor Info - All information REQUIRED for consideration of pull request Joseph Hickey, Vantage Systems, Inc.

[jphickey]

Workflow failure currently reported in this PR should be fixed by my other pending PRs. Once reviewed and merged I this can be rebased.

[jphickey]

Everything rebased and tests/workflows are passing.