Add an Fw::ObjectName implementation of Fw::StringBase

[bocchino]

This way we can replace the char array here

fprime/Fw/Obj/ObjBase.hpp

Line 82 in 20d3a6a

char m_objName[FW_OBJ_NAME_MAX_SIZE]; //!< stores object name

with an Fw::ObjectName object. That will have the following benefits:

1. Avoid direct use of bare string arrays and snprintf.
2. Avoid creating temporary string buffers on the stack to copy strings into the object name.
3. Avoid compiler string truncation warnings. See Increase size of temporary buffer in C++ code gen fpp#383.