Add mmcv libraries to install

[peifferjd]

The current pyproject.toml does not install mmcv versions. I have previously seen success in installing them directly from here instead of using mim, however it was only with mmcv-full. I believe we are ok with using the newer mmcv libraries as @Pouyan97's hand detection uses it and @ktshah04 found a newer halpe detector. We just need to see if we can install the new mmcv from pyproject.