Add HPhi Hubbard momentum standard mode

[tmisawa]

Summary

• Allow HPhi Standard mode MomentumIndex for canonical one-dimensional Hubbard chains.
• Keep the existing Spin guard behavior and split the MomentumIndex validation into Spin and Hubbard model-specific helpers.
• Reject unsupported Hubbard Standard mode combinations, including GC, non-chain lattices, boundary phases, missing fixed nelec/2Sz, longer-range hopping, fields, offsite Coulomb terms, general interactions, pair terms, and unsupported solver methods.

Supported HPhi scope

• model = FermionHubbard or Hubbard
• lattice = chain
• fixed nelec and 2Sz
• Lanczos or CG
• nearest-neighbor hopping and onsite U

Verification

Validated through the dependent HPhi CF4b branch:

• Standard generated qptransidx.def matches hand-written expert-mode TransSym for L=4, nelec=2, 2Sz=0, MomentumIndex=0, U=0.5.
• The MomentumIndex=0 sector matches the TransSym-free full-space reference.
• MomentumIndex=1, U=0 gives the expected sector energy -2.0 and the generated translation character for one-site translation is (0, -1).
• Negative cases reject invalid MomentumIndex, boundary phase, missing 2Sz, offsite Coulomb terms, non-chain lattices, and FullDiag.
• The generated expert input passes serial and MPI checks with 4 and 16 ranks.