[Config] Fix findcxxopt when version is not specified (#4564)

* Remove error and send warning when cxxopt is found but version mismatch

* [all] Install FindTinyXML2  (#4545)

Install FindTinyXML2 for OOT compilation using the binaries

* [Visual] Fix cmake config  (#4555)

Remove the find_package(tinyxml2 REQUIRED) because the link is private

* Set link to tinyxml2 to PRIVATE and fix config file

* Check if version is specified before checking the version to avoid errors

* Set cxx_opts_FOUND when the version is not required

---------

Co-authored-by: Hugo <[email protected]>

Sofa/framework/Config/cmake/Modules/Findcxxopts.cmake

@@ -48,8 +48,12 @@ if(NOT TARGET cxxopts::cxxopts)
   endif()
 
   if(cxxopts_INCLUDE_DIR)
-    _cxxopts_check_version()
-    set(cxxopts_FOUND ${cxxopts_VERSION_OK})
+    if(cxxopts_FIND_VERSION)
+      _cxxopts_check_version()
+      set(cxxopts_FOUND ${cxxopts_VERSION_OK})
+    else()
+      set(cxxopts_FOUND TRUE)
+    endif()
   endif()
 
   if(cxxopts_FOUND)