Add CI tests for optional dependencies - #1654

Addresses part of #1224, #1225 but does not fully close them.

Overview

Provides tests for optional dependencies, as discussed in #1548 (comment). Adds a new CI job step to run these tests. Basically the job steps are:

• (A) make and activate new venv; install without any optional dependencies; run corresponding tests
• (B) make and activate new venv; install with only the viz optional deps; run corresponding tests
• (C) make and activate new venv; install with only the geo optional deps; run corresponding tests
• (D) make and activate new venv; install with the viz and geo optional deps; run corresponding tests

The corresponding tests include checks which:

1. should pass everywhere
2. should pass as long as at least viz is installed
3. should pass as long as at least geo is installed
4. should pass only when both viz and geo are installed

And, "run corresponding tests" attempts all four checks, marking appropriately with with pytest.raises(ImportError) to ensure checks pass/fail as expected. E.g., case (C) marks (2) and (4) with expecting ImportError, but expects (1) and (3) to pass without any issues.

PR Checklist

General

• An issue is created and linked
• Added appropriate labels (if your uxarray repo permissions allow it)
• Filled out Overview and Expected Usage (if applicable) sections

Testing & Benchmarking

• Adequate tests are created if there is new functionality
• Tests are not too basic (such as simply calling a function and nothing else)
• Tests cover all major paths in your new functions
• [N/A] If this PR could affect performance, ran ASV benchmarks and confirmed they show expected behavior (add a new benchmark if necessary)