core: fix function that checks memory leaks in memory pool

Link: https://github.com/GeneAssembly/biosal/issues/788
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
tests: enable unit test for memory pool

Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
core: improve function that detects memory leaks in memory pool

Link: https://github.com/GeneAssembly/biosal/issues/788
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>
tests: add many unit tests for the memory pool test suite

Link: https://github.com/GeneAssembly/biosal/issues/788
Signed-off-by: Sébastien Boisvert <boisvert@anl.gov>