gh-36124: fix cardinality, #36119, #36118, #36116
    
* Fix a thinko in the iterator for TSSCPP
* make plane partitions hashable
* avoid rational numbers in the cardinality methods, when necessary
* raise an error when an integer and a symmetry is provided as argument
to `PlanePartitions`

Fixes #36119
Fixes #36118
Fixes #36116

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URL: #36124
Reported by: Martin Rubey
Reviewer(s): Frédéric Chapoton

Author: Release Manager