fevangelista

Remove SparseHamiltonian, add sign_mask to SparseOperator

2

This pull request removes the `SparseHamiltonian` class and its related functionality from the codebase. It also introduces a new function `sparse_operator_hamiltonian` and updates methods to use this new function. Additionally,...

## Description A brief description of the goals accomplished by this PR ## User Notes - [ ] Features added - [ ] Changes to compilation (if any) ## Checklist...