Move and deprecate dpctl program

[ndgrigorian]

This PR refactors dpctl.program into dpctl.compiler, removing the program submodule

This follows up on previous work to move away from long-deprecated names like program, terminology no longer supported by the SYCL spec.

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[github-actions]

View rendered docs @ https://intelpython.github.io/dpctl/pulls/2317/index.html

[coveralls]

Coverage is 75.023% — move-and-deprecate-dpctl-program into feature/specialization-constants. No base build found for feature/specialization-constants.