Improve cli start-up speed

[johandahlberg]

Description

Since graspologic takes a long time to import we have had those imports done dynamically as they are needed rather than at the module level. This speeds up cli start up times considerably.

I also cleaned out some unused imports.

Fixes: N/A

Type of change

Only changes when things are imported.

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce it when relevant.

PR checklist:

• This comment contains a description of changes (with reason).
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• If a new tool or package is included, I have updated poetry.lock, and cited it properly
• I have checked my code and documentation and corrected any misspellings
• I have documented any significant changes to the code in CHANGELOG.md