Cleans plotting functionality for stocks/sia/metric

[colin99d]

Description

Fixes #2712

How has this been tested?

• Please describe the tests that you ran to verify your changes.
• Provide instructions so we can reproduce.
• Please also list any relevant details for your test configuration.

• Make sure affected commands still run in terminal
  • python terminal.py "/stocks/load CS/sia/clear country/metric roa -l 20" --debug
• Ensure the api still works (Command does not appear in API)
• Check any related reports (Command does not appear in API)

Checklist:

• Update our Hugo documentation following these guidelines.
• Update our tests following these guidelines.
• Make sure you are following our CONTRIBUTING guidelines.
• If a feature was added make sure to add it to the corresponding scripts file.

Others

• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.