VecMem Beta 0.8.0

Release including the following update(s) since v0.7.0:

• Fixes for the SYCL tests to make them (more) compatible with oneAPI's AMD backend support;
• Made vecmem::core require MSVC to set the __cplusplus macro correctly, as a public compiler option;
• Introduced vecmem::cuda::async_copy to allow experimentation with asynchronous memory copies;
• Made GCC/Clang check for missing symbols in the shared libraries built in the project;
• Introduced some benchmarks for "simple" memory allocations;
• Made vecmem::static_array behave even more like std::array, by removing its custom constructors, allowing it to hold non-copyable/non-movable elements as well;
• Made vecmem::cuda::stream_wrapper usable in .cu files on Windows;
• Made it possible to check for memory leaks on NVidia devices in the CUDA tests.