Define a const global for OS_MAX_API_NAME * 2 and use it

[skliper]

Is your feature request related to a problem? Please describe.
Fullname and similar is defined hardcoded as size OS_MAX_API_NAME * 2, example:

cFE/modules/sb/fsw/src/cfe_sb_api.c

Line 100 in c8b5e00

char FullName[(OS_MAX_API_NAME * 2)];

Describe the solution you'd like
Create a const global and use it.

Describe alternatives you've considered
May make sense to actually scrub reporting in APIs to use consistent reporting style/technique. Suspect there's either repetition or variation across the services. Candidate for generic utility function - #994

Additional context
Code review. Note FullName in SB is actually appname.taskname.

Requester Info
Jacob Hageman - NASA/GSFC