build: Added support patches for FreeBSD (#1584)

This pull request fixes build on FreeBSD. The changes are conditioned
with `#if defined(__FreeBSD__)` preprocessor macro and they should not
affect build for other operating systems.

---------

Co-authored-by: Nik <werwolv98@gmail.com>
Co-authored-by: iTrooz <hey@itrooz.fr>

lib/libimhex/source/api/imhex_api.cpp

@@ -658,7 +658,11 @@ namespace hex {
             #if defined(OS_WINDOWS)
                 return "Windows";
             #elif defined(OS_LINUX)
-                return "Linux";
+                #if defined(OS_FREEBSD)
+                    return "FreeBSD";
+                #else
+                    return "Linux";
+                #endif
             #elif defined(OS_MACOS)
                 return "macOS";
             #elif defined(OS_WEB)