Add a UtAssert libc strerror_r stub

[leighgarbs]

Checklist (Please check before submitting)

• I reviewed the Contributing Guide.
• 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

• Fixes Add a UtAssert libc strerror_r stub #1519 by adding a libc strerror_r stub to UtAssert.

Testing performed
I branched cFS and added a few commits demonstrating how this OSAL change enables strerror_r to be covered in unit tests. The cFS branch is add-strerror-r-stub.

The first commit initializes the build. The second commit sets sample_app to a version I've edited to build its unit tests against the UtAssert libc stub library and to have a trivial use of strerror_r. Building this commit fails with:

[ 96%] Building C object apps/sample_app/unit-test/CMakeFiles/coverage-sample_app-sample_app-object.dir/home/lgarbs/cFS/apps/sample_app/fsw/src/sample_app.c.o
/home/lgarbs/cFS/apps/sample_app/fsw/src/sample_app.c: In function 'SAMPLE_APP_Main':
/home/lgarbs/cFS/apps/sample_app/fsw/src/sample_app.c:52:5: error: implicit declaration of function 'strerror_r'; did you mean 'strerror'? [-Werror=implicit-function-declaration]
   52 |     strerror_r(0, error_str, 256);
      |     ^~~~~~~~~~
      |     strerror
cc1: all warnings being treated as errors
make[7]: *** [apps/sample_app/unit-test/CMakeFiles/coverage-sample_app-sample_app-object.dir/build.make:76: apps/sample_app/unit-test/CMakeFiles/coverage-sample_app-sample_app-object.dir/home/lgarbs/cFS/apps/sample_app/fsw/src/sample_app.c.o] Error 1
make[6]: *** [CMakeFiles/Makefile2:10121: apps/sample_app/unit-test/CMakeFiles/coverage-sample_app-sample_app-object.dir/all] Error 2
make[5]: *** [Makefile:146: all] Error 2
make[4]: *** [CMakeFiles/native_default_cpu1-install.dir/build.make:70: CMakeFiles/native_default_cpu1-install] Error 2
make[3]: *** [CMakeFiles/Makefile2:570: CMakeFiles/native_default_cpu1-install.dir/all] Error 2
make[2]: *** [CMakeFiles/Makefile2:260: CMakeFiles/mission-install.dir/rule] Error 2
make[1]: *** [Makefile:192: mission-install] Error 2
make: *** [Makefile:126: install] Error 2

The third commit sets OSAL to the commit on this PR, and should build.

The actual build steps are:

make SIMULATION=native ENABLE_UNIT_TESTS=true prep
make install

Expected behavior changes

• API Change: Adds OCS_strerror_r and strerror_r to the API exposed to UtAssert unit tests that build against the libc stub library.
• Behavior Change: UtAssert unit tests of content using the libc strerror_r function build, and strerror_r is stub-able.

System(s) tested on

• Hardware: PC
• OS: Ubuntu 22.04
• Versions: the current development version of cFS, plus sample_app and OSAL version changes as described in the "Testing performed" section above

Contributor Info - All information REQUIRED for consideration of pull request
Leigh Garbs, NASA