- The compiler module only contains the compiler pipeline
     to compiler SpirvKernel objects.

   - Creates a separate module for the unpack and pack
     functions for kernel arguments.
   - The new API is intended for use from the Dispatcher class.

  - The concept of a kernel was decoupled from the notion of
    dispatching of a kernel. The present implementation in
    compiler.py intermixes both things, making hard the
    separation of compute-follows-data based kernel launch
    and legacy `dpctl.device_context` based behavior.
  - Deprecates support for numpy arrays as kernel args.
  - Deprecates support for the square bracket notation using
    `__getitem__` to provide global and local ranges for a
    kernel launch.
  - Changes the behavior of specializing a kernel using only
    a signature. The new way to specialize will require a
    device type and a backend.
  - Improvements to exception messages using custom exceptions.
  - The new API is now inside `numba_dpex.core.kernel_interface`.

Fix docs rst

   - Kernel specialization for specific signatures was fixed.
   - Specialization is only allowed for usm_ndarray.
   - Dispacther class was renamed as JitKernel.
   - decorators updated.

   - print a better type name with keywords and all attributes.
   - store a fully qualified filter string in the type.
   - set the default address space to GLOBAL instead of None.
   - fix the unify function to test on usm_type, device, address
     space.

   - Added unit tests for the kernel specialization feature.
   - Fix kernel decorator to support list of signatures.
   - Disallow JIT compilation of a specialized kernel and raise
     an exception.

    - Move sycl_usm_array_interface helper functions into core/utils.
    - Move array type conversion function for unknown type with
      sycl_usm_array_interface to UsmNdArray into core/typeconv.
    - Fix how the UsmNdArray type is constructed for unknow
      sycl_usm_array_interface arrays.

…ion using strings.

   - Move compile_with_dpex into the core.compiler module.
   - The target and typing contexts are now not set from dpex_target
     inside the SpirvKernel.compile. They are passed in as args.
   - Fix tests impacted by these changes.

Removed test_black_scholes.py.
Renamed dppy to dpex in two test files.

   - The compute follows data checking is now based on queue
     equality.
   - USMNdArray no longer requires usm_type and device
     during construction. It allows us to specialize an usm_ndarray
     only on ndims, layout and dtype.
   - No check for compute follows data for eager compilation.
   - Change caching to not require backend and device-type.
   - Fixes to test cases.

…Python/numba-dpex into refactor/kernel_interfaces

…Python/numba-dpex into refactor/kernel_interfaces