Need to check 'is_applicable' for known_memberships in linear_algebra and quantum algebra packages

[wwitzel]

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InClass.yield_known_memberships does this properly where it checks 'is_applicable'. However, this doesn't appear done properly for yield_known_hilbert_spaces in the linear_algebra package or when using MatrixSpace.known_memberships in qmult.py. This can cause funny behavior when assumptions change. There may be other places where this is done incorrectly.