Update various api endpoints documentation

[crugas]

Updates to various API endpoints documentation to help clarify use for users.

Description

Updates to the following API endpoints documentation:

• date_calculator.rb: Added SHELL and Python examples
• extent_calculator.rb: Added brief statement to description clarifying units of measurements
• external_id.rb: Added SHELL and Python examples
• version.rb: Added SHELL and Python examples

Related JIRA Ticket or GitHub Issue

API Documentation Subgroup

How Has This Been Tested?

N/A

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have read the CONTRIBUTING document.
• I have authority to submit this code.
• I have added tests to cover my changes.
• All new and existing tests passed.