Improve API consistency for functions accepting a software bus message

[jphickey]

Is your feature request related to a problem? Please describe.
The data types accepted by the SB API are not entirely consistent. Most API functions that operate on software bus message buffers accept a CFE_SB_MsgPtr_t.

There are some exceptions, most notably the CFE_SB_InitMsg() function accepts a void*.

Describe the solution you'd like
All SB API functions that operate on message buffers should use the CFE_SB_MsgPtr_t type (or CFE_SB_Msg_t *)

Additional context
Making the interface type-correct helps the compiler's type checking do its intended job, helping to catch/avoid the possibility of passing a data buffer which is not actually an SB message buffer. Using void* permits anything to be passed in, effectively disabling all checking.

Requester Info
Joseph Hickey, Vantage Systems, Inc.

[skliper]

CFE_SB_InitMsg was deprecated in #998, no remaining instances found of using void * with msg.