[develop2] detect_compiler() detects invalid 'settings.compiler.version' for apple-clang

[yzakharchuk]

detect_compiler() takes only major version of apple-clang which is invalid.

$ clang --version
Apple clang version 12.0.0 (clang-1200.0.32.2)
$ git clone https://github.com/conan-io/cmake-conan.git -b develop2
$ cd cmake-conan/example
$ mkdir build
$ cmake -G Xcode -B build -S . -DCMAKE_PROJECT_TOP_LEVEL_INCLUDES=../conan_provider.cmake -DCMAKE_BUILD_TYPE=Release

Output log

-- The CXX compiler identification is AppleClang 12.0.0.12000032
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- CMake-Conan: first find_package() found. Installing dependencies with Conan
-- CMake-Conan: Checking if a default profile exists
ERROR: Profile not found: default
-- CMake-Conan: The default profile doesn't exist, detecting it.
detect_api: Found apple-clang 12.0

Detected profile:
WARN: This profile is a guess of your environment, please check it.
WARN: Defaulted to cppstd='gnu17' for apple-clang.
WARN: The output of this command is not guaranteed to be stable and can change in future Conan versions.
WARN: Use your own profile files for stability.
Saving detected profile to /______/.conan2/profiles/default
[settings]
arch=x86_64
build_type=Release
compiler=apple-clang
compiler.cppstd=gnu17
compiler.libcxx=libc++
compiler.version=12.0
os=Macos

-- CMake-Conan: cmake_system_name=Darwin
-- CMake-Conan: cmake_osx_deployment_target=
-- CMake-Conan: cmake_system_processor=x86_64
-- CMake-Conan: CMake compiler=AppleClang
-- CMake-Conan: CMake compiler version=12.0.0.12000032
-- CMake-Conan: [settings] compiler=apple-clang
-- CMake-Conan: [settings] compiler.version=12
CMake Warning at /______/cmake-conan/conan_provider.cmake:296 (message):
  CMake-Conan: The C compiler is not defined.  Please define CMAKE_C_COMPILER
  or enable the C language.
Call Stack (most recent call first):
  /______/cmake-conan/conan_provider.cmake:375 (append_compiler_executables_configuration)
  /______/cmake-conan/conan_provider.cmake:522 (detect_host_profile)
  CMakeLists.txt:7 (find_package)


-- CMake-Conan: Creating profile /______/cmake-conan/example/build/conan_host_profile
-- CMake-Conan: Profile:
[settings]
arch=x86_64
os=Macos
compiler=apple-clang
compiler.version=12
compiler.cppstd=14
compiler.libcxx=libc++
[conf]
tools.cmake.cmaketoolchain:generator=Xcode

CMake Warning at /______/cmake-conan/conan_provider.cmake:535 (message):
  Cmake-conan: CMakeDeps generator was not defined in the conanfile.  Please
  define the generator as it will be mandatory in the future
Call Stack (most recent call first):
  CMakeLists.txt:7 (find_package)


-- CMake-Conan: Installing both Debug and Release
-- CMake-Conan: conan install /______/cmake-conan/example -of=/______/cmake-conan/example/build/conan --profile:host=default;--profile:host=/______/cmake-conan/example/build/conan_host_profile;--profile:build=default;-s;build_type=Release;--build=missing;-g;CMakeDeps
ERROR: Invalid setting '12' is not a valid 'settings.compiler.version' value.
Possible values are ['5.0', '5.1', '6.0', '6.1', '7.0', '7.3', '8.0', '8.1', '9.0', '9.1', '10.0', '11.0', '12.0', '13', '13.0', '13.1', '14', '14.0', '15', '15.0']
Read "http://docs.conan.io/2/knowledge/faq.html#error-invalid-setting"
CMake Error at /______/cmake-conan/conan_provider.cmake:436 (message):
  Conan install failed='1'
Call Stack (most recent call first):
  /______/cmake-conan/conan_provider.cmake:546 (conan_install)
  CMakeLists.txt:7 (find_package)