Milestone 1.11

[tony]

• split Command CLI CLI: Break up into modules #762
• improve test fixtures Refactor tests/ fixture and constants access #761
• autocompletion CLI: Split cli.py into modules #765

Deferred to later milestones

• Version alternative: Fix distutils.version.Version deprecation warning (python 3.10) #727 #764
• Test /examples files in pytest Test /examples in pytest #780