dependency.dav1d.cmake: refine meson --buildtype mapping

[ShamrockLee]

CMAKE_BUILD_TYPE supports more values than Debug and Release according to its CMake documentation, and so does the Meson buildtype.

This PR adds a function meson_build_type_from_cmake to set corresponding Meson buildtype for each typical CMAKE_BUILD_TYPE value and make DAVID_MESON_BUILDTYPE overridable.

[agruzdev]

Hello!
The build type mapping looks fine, but seems to be not used. When I try to build MinSizeRel

cmake --build . --config MinSizeRel

The dav1d library is still compiled as debug and release only:

Seems it should be adjusted further

Using MSVC 2022

[ShamrockLee]

Thank you for testing and sorry for late response.

Unlike the if (UNIX) block, the --buildtype of the if (MSVC) block is hard-coded to debug and release, which are then used to specify DAVID_LIBRARY and DAVID_DEBUG_LIBRARY.

Considering than only DAVID_LIBRARY is used when building LibHEIF, should we align the align its behavior with the UNIX one and respect the global CMAKE_BUILD_TYPE specification?

[ShamrockLee]

The MSVC build now produces build_debug and build_${DAVID_MESON_BUILDTYPE} when DAVID_MESON_BUILDTYPE is not "debug".