Resolve "The C++ API should not rely on `unique_ptr`"

This MR removes the need to pass a std::unique_ptr<admire::storage> argument to register_adhoc_storage in the C++ API.

Tests are also updated to reflect this change and to remove dependencies with ADM_storage_create(), which in the future will become an internal function.

Finally, we fix some use-after-free memory management errors due to shortcomings in managed_ctypes and the creation function of C API types themselves. The errors are "fixed" by not deleting the data, which means that we are now effectively leaking. So that tests pass, we set detect_leaks=0 in ASAN_OPTIONS.

Closes #47 (closed)