Cmake: include check_symbol_exists in fmt cmakeLists txt file to fix cmake under windows (#466)

Selecting Windows SDK version 10.0.26100.0 to target Windows 10.0.26200.
The C compiler identification is MSVC 19.44.35222.0
The CXX compiler identification is MSVC 19.44.35222.0
Detecting C compiler ABI info
Detecting C compiler ABI info - done
Check for working C compiler: C:/Program Files/Microsoft Visual Studio/2022/Community/VC/Tools/MSVC/14.44.35207/bin/Hostx64/x64/cl.exe - skipped
Detecting C compile features
Detecting C compile features - done
Detecting CXX compiler ABI info
Detecting CXX compiler ABI info - done
Check for working CXX compiler: C:/Program Files/Microsoft Visual Studio/2022/Community/VC/Tools/MSVC/14.44.35207/bin/Hostx64/x64/cl.exe - skipped
Detecting CXX compile features
Detecting CXX compile features - done
Detected 64-bit platform
MSVC: Minimum version required is 19.32, found 19.44.35222.0 - ok!
MSVC: 64-bit platform, enforced -D_WIN64 parameter
MSVC: Enabled increased number of sections in object files
MSVC: Overloaded standard names
MSVC: Disabled NON-SECURE warnings
MSVC: Disabled POSIX warnings
MSVC: Disabled generic compiletime warnings
Found MySQL:
Found Git: C:/Program Files/Git/cmd/git.exe (found suitable version "2.47.0.windows.2", minimum required is "1.7")
Found MySQL:   found components: binary
Found MySQL executable: C:/Program Files/MySQL/MySQL Workbench 8.0 CE/mysql.exe

* TrinityCore revision   : 716f480b79 2026-05-05 11:31:32 +0200 (master branch)

* Install core to        : C:/Program Files (x86)/TrinityCore

* Build world/auth       : Yes (default)
* Build with scripts     : Yes (static)
* Build map/vmap tools   : Yes (default)
* Build unit tests       : No (default)
* Unity build enabled    : No (default)
* Build core w/PCH       : Yes (default)
* Build scripts w/PCH    : Yes (default)
* Show compile-warnings  : No  (default)
* Use coreside debug     : No  (default)
* Show source tree       : Yes (hierarchical)
* Use GIT revision hash  : Yes (default)

Performing Test CMAKE_HAVE_LIBC_PTHREAD
Performing Test CMAKE_HAVE_LIBC_PTHREAD - Failed
Looking for pthread_create in pthreads
Looking for pthread_create in pthreads - not found
Looking for pthread_create in pthread
Looking for pthread_create in pthread - not found
Found Threads: TRUE
Boost toolset is unknown (compiler MSVC 19.44.35222.0)
Boost toolset is unknown (compiler MSVC 19.44.35222.0)
Boost toolset is unknown (compiler MSVC 19.44.35222.0)
Boost toolset is unknown (compiler MSVC 19.44.35222.0)
Boost toolset is unknown (compiler MSVC 19.44.35222.0)
Boost toolset is unknown (compiler MSVC 19.44.35222.0)
Boost toolset is unknown (compiler MSVC 19.44.35222.0)
Boost toolset is unknown (compiler MSVC 19.44.35222.0)
CMake Error at dep/fmt/CMakeLists.txt:18 (check_symbol_exists):
  Unknown CMake command "check_symbol_exists".

Configuring incomplete, errors occurred!

Co-authored-by: FlyingArowana <TheSCREWEDSoftware@users.noreply.github.com>

dep/fmt/CMakeLists.txt

@@ -10,6 +10,8 @@
 
 set(strtod_l_headers stdlib.h)
 
+include(CheckSymbolExists)
+
 if (APPLE)
   set(strtod_l_headers ${strtod_l_headers} xlocale.h)
 endif ()