Flashlight library Files

This is a patch release that will be the last release before breaking changes to Flashlight given the Flashlight Tensor framework (fl::Tensor). This and other patch releases to v0.3.x will be updated as needed in the 0.3 branch, which will diverge from main.

Fixes in this release include: - Build fixes, removing empty target issues for install (#834) - Updates to Google Mock syntax to require a minimum version of 1.10. - An updated CITATION file for citing FL - Updates to CircleCI per breaking changes - Improvements to CMake BLAS lib locating (#806) - Fix gradient computation for batched matrix multiply (#760) - Refactoring Flashlight components into a pkg-based layout (#713)

This release contains improvements to the Flashlight Tensor API (flashlight/fl/tensor) including: - A roll operator for Tensor - Fixes to static initialization for ArrayFireBackend state - Fixes to the concatenate operation with the ArrayFireBackend - Better Tensor and Shape stringification functions (#808) - TensorBackend::isDataTypeSupported() - TensorBackend::getDeviceCount() - Adds a sorting operation that returns both values and indices (#809) - Better protection for OOB indexing on a Shape (#810) - The TensorExtension API for autograd and vision primitives (#762) - Scalar exponentiation by a tensor (#774) - Tensor broadcasting for binary ops (#775) - A scalar (0D) tensor type - A flip operator (#766) - Rounding and cumsum operators - Reductions that return host-side primitives now return Tensors (#755)