Paths API Commands in Tethys CLI

[jakeymac]

Description

This pull request adds new functionality to Tethys CLI, allowing users to:

• Retrieve file paths in the Tethys Paths API
• Add files easily to file paths in the Tethys Paths API

It also provides small updates to the Paths API workspace functions

Changes Made to Code

• Added new commands to Tethys CLI
• Small updates to Paths API in workspace functions to accept TethysApp objects/models

Related PRs, Issues, and Discussions

• [FEATURE] Workspaces CLI Command #1196

Quality Checks

• At least one new test has been written for new code
• New code has 100% test coverage
• Code has been formatted with Black
• Code has been linted with flake8
• Docstrings for new methods have been added
• The documentation has been updated appropriately