Clean up SC_NUMBER_OF_RTS_IN_UINT16 define

[jphickey]

Checklist (Please check before submitting)

• I reviewed the Contributing Guide.
• I reviewed the README file to see if the feature is in the major future work.
• I performed a cursory search to see if the feature request is relevant, not redundant, nor in conflict with other tickets.

Is your feature request related to a problem? Please describe.
This define is basically "duplicate information" -- there are always 16 bits in a uint16.

Describe the solution you'd like
Instead, the code should deduce how many bits are in each array element via sizeof(), rather than relying on some other macro that may (or may not) be set correctly.

This definition should be removed, and references to it should be replaced with a more robust method.

Additional context
This is a portability issue, and also makes assumptions about how the bits are encoded into TLM that may not be correct going forward.

Requester Info
Joseph Hickey, Vantage Systems, Inc.