Rich output code cordoning, HTML image fix

[softwareengineerprogrammer]

Description

The existing implementation of rich output is duplicative of Outputs.PrintOutputs. This adds undue code complexity, maintenance overhead, inconsistency, and potential for bugs. Rich output should instead be generated in a module that uses GeophiresXClient or an equivalent pattern which maintains Outputs.PrintOutputs as the ultimate source of truth/authority for output logic. (Somewhat conceptually tangentially relevant to NREL#9)

This change:

1. Adds a TODO regarding the above issue
2. Cordons off rich output logic in a separate OutputsRich.py file to help mitigate some of the mental overhead/tedious code navigation issues associated with the current implementation. For instance in NREL@aeec33d (Miscellaneous fixes/updates [v3.8.9] NREL/GEOPHIRES-X#372), I initially searched code for "Thickness" to find where it is output; this search would have been more efficient if I could have quickly seen that half the results were simply duplicated rich output logic by virtue of being in OutputsRich.py.
3. Includes a fix for a pre-existing issue with rich HTML images

Testing & Validation

No unit tests were affected because no test coverage was added when rich output was implemented. A basic sanity-check test was added post-facto which ensures that a rich output HTML file is generated if specified in parameters and that it includes a case report header in expected format.

I looked at rich HTML output and noticed that images weren't included correctly, and a fix for that is included in this PR. Rich HTML output now appears as expected:

I briefly manually looked at rich text output in the console and it appeared as expected: