Address several old issus higher-order FEM, poisson tests, and testing problems

[cekees]

Mandatory Checklist

Please ensure that the following criteria are met:

• Title of pull request describes the changes/features
• Request at least 2 reviewers
• If new files are being added, the files are no larger than 100kB. Post the file sizes.
• Code coverage did not decrease. If this is a bug fix, a test should cover that bug fix. If a new feature is added, a test should be made to cover that feature.
• New features have appropriate documentation strings (readable by sphinx)
• Contributor has read and agreed with CONTRIBUTING.md and has added themselves to CONTRIBUTORS.md

As a general rule of thumb, try to follow PEP8 guidelines.

Description

Initial work to close out #14, #15, and #16. Mainly fixing the tests themselves and petsc options. In the process I found that the DG archiving had never been properly updated and that a larger DG boundary penalty improves conditioning. There were some messy test interactions that caused other changes--a project for the future. On a positive note, @ejtovar @jhcollins @zhang-alvin I used the pytest parameterized testing support to generate more comprehensives tests here: https://github.com/erdc/proteus/pull/1206/files?file-filters%5B%5D=.csv&file-filters%5B%5D=.py#diff-50950c09443ffea929f7eb626c9cb336. It's nothing new but might be a useful example for you when writing tests. It replaces the old "yield tests".

[zhang-alvin]

I saw that there were slight changes in how the petsc options were being loaded into the tests, or at least the defaults were reset. Does that resolve #1184 on an individual test level?

[cekees]

I saw that there were slight changes in how the petsc options were being loaded into the tests, or at least the defaults were reset. Does that resolve #1184 on an individual test level?

No, not really. I think that issue needs a more comprehensive review of how they're being set/loaded and a good across-the-board cleanup of that issue.