Relocate CPF Read + Power Strap Issues

[kenhoberkeley]

Related PRs / Issues

• CPF intent can only be read when after ILM flattening. It is not possible to flatten ILMs before floorplanning. Hence, move the CPF read to later in the flow.
• Power straps continue to interact with routing within the halos. Proposed solution is like so: 1) Routing halo generation remains the same. Placement halo is slightly increased in size. A power routing blockage is then created in same shape as the placement halo. This allows router to avoid power straps in a non-routing-halo region, before subsequently entering the halo region (this seems to work better). Also, enforce situations where pins for power and signal generated together on a layer.

Type of change:

• [X ] Bug fix
• New feature
• Other enhancement

Impact:

• Change to core Hammer
• [X ] Change to a Hammer plugin
• Other

Contributor Checklist:

• [X ] Did you set master as the base branch?
• [X ] Did you state the type-of-change/impact?
• [ X] Did you delete any extraneous prints/debugging code?
• [ X] (If applicable) Did you add documentation for the feature?
• [ X] (If applicable) Did you update the poetry.lock file if you updated the requirements in pyproject.toml?
• [ X] (If applicable) Did you add a unit test demonstrating the PR?
• [ X] (If applicable) Did you run this through the e2e integration tests?
• [ X] (If applicable) Did you update the submodules in e2e/ if this feature depends on updated plugins?