gh-35629: Implement the exceptional Jordan algebra
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### :books: Description
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"The" exceptional Jordan algebra is a 27 dimensional algebra defined as
the $3 \times 3$ self-adjoint matrices over the octonions. This is an
important Jordan algebra as it is used to construct the simple Lie
group/algebra of type $F_4$.
Fixes #32940.
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### :hourglass: Dependencies
- #35630 used in the construction
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URL: https://github.com/sagemath/sage/pull/35629
Reported by: Travis Scrimshaw
Reviewer(s): Frédéric Chapoton, Matthias Köppe, Travis Scrimshaw
