Build: Update required cmake version to 3.18

* Remove cotire

# Conflicts:
#	dep/PackageList.txt

cmake/macros/FindPCHSupport.cmake

@@ -1,35 +1,20 @@
-if(CMAKE_VERSION VERSION_LESS "3.16.0")
-  if(MSVC)
-    # Specify the maximum PreCompiled Header memory allocation limit
-    # Fixes a compiler-problem when using PCH - the /Ym flag is adjusted by the compiler in MSVC2012,
-    # hence we need to set an upper limit with /Zm to avoid discrepancies)
-    # (And yes, this is a verified, unresolved bug with MSVC... *sigh*)
-    #
-    # Note: This workaround was verified to be required on MSVC 2017 as well
-    set(COTIRE_PCH_MEMORY_SCALING_FACTOR 500)
-  endif()
+# This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the
+# Free Software Foundation; either version 2 of the License, or (at your
+# option) any later version.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+# FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+# more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program. If not, see <http://www.gnu.org/licenses/>.
 
-  include(cotire)
-
-  function(ADD_CXX_PCH TARGET_NAME_LIST PCH_HEADER)
-    # Use the header for every target
-    foreach(TARGET_NAME ${TARGET_NAME_LIST})
-      # Disable unity builds
-      set_target_properties(${TARGET_NAME} PROPERTIES COTIRE_ADD_UNITY_BUILD OFF)
-
-      # Set the prefix header
-      set_target_properties(${TARGET_NAME} PROPERTIES COTIRE_CXX_PREFIX_HEADER_INIT ${PCH_HEADER})
-
-      # Workaround for cotire bug: https://github.com/sakra/cotire/issues/138
-      set_property(TARGET ${TARGET_NAME} PROPERTY CXX_STANDARD 17)
-    endforeach()
-
-    cotire(${TARGET_NAME_LIST})
-  endfunction(ADD_CXX_PCH)
-else()
-  function(ADD_CXX_PCH TARGET_NAME_LIST PCH_HEADER)
-    foreach(TARGET_NAME ${TARGET_NAME_LIST})
-      target_precompile_headers(${TARGET_NAME} PRIVATE ${PCH_HEADER})
-    endforeach()
-  endfunction(ADD_CXX_PCH)
-endif()
+function(ADD_CXX_PCH TARGET_NAME_LIST PCH_HEADER)
+  foreach(TARGET_NAME ${TARGET_NAME_LIST})
+    target_precompile_headers(${TARGET_NAME} PRIVATE ${PCH_HEADER})
+  endforeach()
+endfunction(ADD_CXX_PCH)