MAINT: Add assignment operators for Input and Parameter classes of solvers

[david-cortes-intel]

Description

Should solve issues with static analyzers pointing out that there are copy constructors without assignment operators for many of the Input and Parameter class used in optimization routines and which are exported.

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[david-cortes-intel]

Changed the scope of the PR to modify several classes instead of just one.

[david-cortes-intel]

/intelci: run