POSIX specifies strcasecmp/strncasecmp in <strings.h>, not <string.h>.
On NuttX (and other strict POSIX environments) rcutils/src/strcasecmp.c
only includes <string.h>, causing an implicit-declaration error for
strcasecmp when cross-compiling.
Patch 0003 adds #include <strings.h> guarded by !_WIN32, matching the
existing Windows/POSIX split in the file.
Signed-off-by: Arjav Patel <arjav1528@gmail.com>
