Update minimum CMake version to 3.10

[poyo86]

Closes #305

[poyo86]

cmake/switch.toolchain.cmake minimum version is also outdated. Should it be also addressed in this pull request?

[xordspar0]

This builds for me, but FYI, there's still a warning that 3.5 is also deprecated:

CMake Deprecation Warning at CMakeLists.txt:1 (cmake_minimum_required):
  Compatibility with CMake < 3.10 will be removed from a future version of
  CMake.

[poyo86]

This builds for me, but FYI, there's still a warning that 3.5 is also deprecated:

CMake Deprecation Warning at CMakeLists.txt:1 (cmake_minimum_required):
  Compatibility with CMake < 3.10 will be removed from a future version of
  CMake.

I thought that specifying 3.5 instead of 3.10 would be better for compatibility, however now checking repology I can see that basically everyone moved past version 3.10, so this shouldn't be an issue