Refactor e2e & Joules Plugin

[nayiri-k]

This PR adds many more capabilities to the e2e tests, so that we can easily run flows for different designs/pdks/tools. The e2e/README summarizes how to run this flow. The PR also adds several features to the Cadence Joules power plugin, including writing database checkpoints between power steps, and supporting several reporting output formats (notably power profile instead of average power reporting).

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]

Looks great! Some global comments:
 

1. With these updates to the README, I think we can directly include it into the readthedocs (instead of reference). See this folder for an example for how to symlink the Markdown file: https://github.com/ucb-bar/hammer/tree/master/doc/Technology.
2. test seems like it should be called pass? Perhaps this directory should actually be using the nop tools and techs so that it can truly be used for testing w/o any plugin dependencies. Then the power ymls should apply to GCD instead.

[dpgrubb13]

Just change the few nits. Looks great!