refactor: add sodium-internal to cmake and re-import as sodium crypto sign

libsession-util/src/main/cpp/CMakeLists.txt

@@ -63,6 +63,7 @@ target_link_libraries( # Specifies the target library.
         PUBLIC
         libsession::config
         libsession::crypto
+        libsodium::sodium-internal
         # Links the target library to the log library
         # included in the NDK.
         ${log-lib})

libsession-util/src/main/cpp/util.cpp

@@ -1,6 +1,5 @@
 #include "util.h"
-//#include <sodium/crypto_sign.h>
-#include "../../../libsession-util/external/libsodium-internal/src/libsodium/include/sodium/crypto_sign.h"
+#include <sodium/crypto_sign.h>
 #include <string>
 
 namespace util {