[Trivial] Document that more EvolutionDriver functions are overridable

[bprather]

@pgrete brings up the excellent point we should mention which functions are available to override in EvolutionDriver now in the docs. There's even a quite convenient place to do so, so here's that.

Also previous PR had some tests failing, so this can serve to check whether those were just the AMD CI issues, or something substantial. (I can't imagine marking a method virtual in a class with no children could have broken anything though?)

PR Checklist

• Code passes cpplint
• New features are documented.
• Adds a test for any bugs fixed. Adds tests for new features.
• Code is formatted
• Changes are summarized in CHANGELOG.md
• Change is breaking (API, behavior, ...)
  • Change is additionally added to CHANGELOG.md in the breaking section
  • PR is marked as breaking
  • Short summary API changes at the top of the PR (plus optionally with an automated update/fix script)
• CI has been triggered on Darwin for performance regression tests.
• Docs build
• (@lanl.gov employees) Update copyright on changed files