Add compatibility with Sundials 7.0

[speth]

Changes proposed in this pull request

This PR adds compatibility with Sundials 7.0 which introduces a couple of breaking changes. Specifically:

• Changes to the signature of SUNContext_Create
• Changes to the signature of error handling callback functions
• The addition of the sundials_core library that needs to be linked for any Sundials usage
• Removal of some previously-deprecated typedefs (such as realtype) and headers (such as cvodes_direct.h)

Currently, this is not tested as part of CI since there are no conda-forge packages for the release candidate. I figure we can wait and merge this after the full release when those packages are available.

Checklist

• [x] The pull request includes a clear description of this code change
• [x] Commit messages have short titles and reference relevant issues
• [x] Build passes (scons build & scons test) and unit tests address code coverage
• [x] Style & formatting of contributed code follows contributing guidelines
• [x] The pull request is ready for review

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 72.76%. Comparing base (b0ba90a) to head (927f943).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1672 +/- ## ======================================= Coverage 72.76% 72.76% ======================================= Files 378 378 Lines 56986 56986 Branches 20691 20691 ======================================= Hits 41468 41468 Misses 12463 12463 Partials 3055 3055 ```

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