Add a history and average of the last X code execution times

[MHendricks]

Keeps track of the execution time of the last X commands run. If you click on the status bar it will open a menu showing each data point and the average of all of them. You can also set the number of entries to keep.

Checklist

• I have read the CONTRIBUTING.md document
• I formatted my changes with black
• I linted my changes with flake8
• I have added documentation regarding my changes where necessary
• Any pre-existing tests continue to pass
• Additional tests were made covering my changes

Types of Changes

• Bugfix (change that fixes an issue)
• New Feature (change that adds functionality)
• Documentation Update (if none of the other choices apply)

Proposed Changes