Refactor common compiler phases among different backends to drivers.common.compiler.phases package and restructure compiler utilities

[mikepapadim]

This PR refactors common compiler phases among all backends to be moved under drivers.common package to reduce code duplication. Also, cleanups sketch tier phases under the runtime package.

Backend/s tested

Mark the backends affected by this PR.

• [x] OpenCL
• [x] PTX
• [x] SPIRV

OS tested

Mark the OS where this PR is tested.

• [x] Linux
• [ ] OSx
• [ ] Windows

Did you check on FPGAs?

If it is applicable, check your changes on FPGAs.

• [ ] Yes
• [x] No

How to test the new patch?

## Pass Unittests using the OpenCL backend
$ make BACKEND=opencl
$ make tests

## If the changes are also applicable to the PTX backend: 
## Pass unittests using the PTX backend
$ make BACKEND=ptx
$ make tests 

## If the changes are also applicable to the SPIR-V backend: 
## Pass unittests using the SPIRV backend
$ make BACKEND=spirv
$ make tests 

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[CLAassistant]

All committers have signed the CLA.

[mikepapadim]

This is ready for review

[jjfumero]

All unitests passing + KFusion + RayTracer

[jjfumero]

LGTM. thanks @mikepapadim