Units Overhaul

[harrisonliew]

Follow-on to #798, some other small fixes:

• Cap/time units should be derived from technology libs to calculate generated SDC constraints. Also do not override units in tools. See comment below for reasoning. Closes Eventually remove time unit from the tech json #519
• get_db hports in SDC causes segfault - log an error
• Genus can now also read power intent and insert cells
• Take out annoying "not associated with a type" warning
• Ignore decoding errors from stdout

Investigating if grid unit should also be removed and derived from tech LEF.

Related PRs / Issues

Type of change:

• Bug fix
• New feature
• Other enhancement

Impact:

• Change to core Hammer
• Change to a Hammer plugin
• Other

Contributor Checklist:

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

[harrisonliew]

Just found out that Innovus cannot support set_units in SDC files: https://community.cadence.com/cadence_technology_forums/f/digital-implementation/56914/how-to-set-the-units-for-an-sdc-file-in-innovus-warn-tclcmd-1461-skipped-unsupported-command-set_units

Furthermore, units are derived from the lib files: https://support.cadence.com/apex/ArticleAttachmentPortal?id=a1Od0000000nWFbEAM&pageName=ArticleContent

Also, it segfaults with get_db hports.