Delete signed integer test and implementation.

Removed the `daw_integers_signed_test.cpp` and `daw_signed.h` files. This commit eliminates the signed integer testing and the corresponding implementation, likely due to refactoring or deprecated functionality.

Author: beached

CMakeLists.txt

@@ -9,7 +9,7 @@
 cmake_minimum_required( VERSION 3.14 )
 
 project( "daw-header-libraries"
-         VERSION "2.113.1"
+         VERSION "2.114.0"
          DESCRIPTION "Various headers"
          HOMEPAGE_URL "https://github.com/beached/header_libraries"
          LANGUAGES C CXX