[ODESolver] Rename files to match class name

[alxbilger]

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Reviewers will merge this pull-request only if

• it builds with SUCCESS for all platforms on the CI.
• it does not generate new warnings.
• it does not generate new unit test failures.
• it does not generate new scene test failures.
• it does not break API compatibility.
• it is more than 1 week old (or has fast-merge label).

[hugtalbot]

Would you mind adding the C++/CMake compatibility layer? :pray: I can take over if you need it

[alxbilger]

@hugtalbot What is missing?

[bakpaul]

I guess nothing is missing ?

[fredroy]

[ci-build][with-all-tests]