Split convolution library by data layout.

[illsilin]

Proposed changes

One of the few libraries that still consumes CK static libs, MIOpen, is currently only using the convolution library, and it only needs certain data layouts. So we've decided to split device_conv_operations into several parts: device_conv_gnwc_operations device_conv_nwgc_operations device_conv_nhwgc_operations device_conv_ngchw_operations device_conv_gnhwc_operations device_conv_gndhwc_operations device_conv_ndhwgc_operations device_conv_ngcdhw_operations device_conv_old_operations

The last one "device_conv_old_operations" contains all the non-grouped convolutions + grouped_convnd_bwd instances, which don't fall into any of the 1d/2d/3d combinations. Each new library can thus be built and linked independently, which will save time. At the same time, we maintain an interface for device_conv_operations, which will include all or some of the above libs (not all libs get built for all device architectures).

Checklist

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• [x] I have added tests relevant to the introduced functionality, and the unit tests are passing locally
• [x] I have added the test to REGRESSION_TESTS list defined at the top of CMakeLists.txt in tests/CMakeLists.txt, IF the test takes more than 30 seconds to run.
• [x] I have added inline documentation which enables the maintainers with understanding the motivation
• [x] I have removed the stale documentation which is no longer relevant after this pull request
• [x] (If this change is user-facing) I have added release notes which provide the end users with a brief summary of the improvement from this pull request
• [x] I have run clang-format on all changed files
• [x] Any dependent changes have been merged