GitLab

- incorrect PAHO_found detection leaded to define MQTT even without Paho available
- use paho cmake config file instead of defining a cmake find file

Compilation of Expat as a static library is not functional. Minor fix to could run tests in CI with shared version.

Functions SOPC_strtoint and SOPC_strtouint were not checking parameters and did not return false in cases of overflow.
Moreover on windows system, the 64 bits integer were not supported (32 bits minimum / maximum were returned in case of overflow).

Fix an issue when using S2OPC dependencies in a CMake project for a user application.

Fix a warning raised by CMake in further version (tested in 3.17):
CMake Warning (dev) at /usr/local/share/cmake-3.17/Modules/FindPackageHandleStandardArgs.cmake:272 (message):
  The package name passed to find_package_handle_standard_args (MBEDTLS)
  does not match the name of the calling package (MbedTLS).  This can lead to
  problems in calling code that expects find_package result variables
  (e.g., _FOUND) to follow a certain pattern.
Call Stack (most recent call first):
  CMake/FindMbedTLS.cmake:41 (find_package_handle_standard_args)
  CMakeLists.txt:16 (_find_package)
  src/Common/CMakeLists.txt:15 (find_package)
This warning is for project developers.  Use -Wno-dev to suppress it.

Force to use the Expat CMake config mode to avoid conflicts with module mode

Ticket #757: demo client: define common connections arguments and use argument parser helper for s2opc_read

Since SOPC_UsersConfig could be deallocated by user authentication manager, avoid to return it for deallocation