refactor: set Structure._loiDebit to private, add setter to update properties

src/structure/structure.ts

src/structure/structure_gate_cem88d.ts

src/structure/structure_gate_cem88v.ts

src/structure/structure_gate_cunge80.ts

src/structure/structure_kivi.ts

src/structure/structure_orifice_free.ts

src/structure/structure_orifice_submerged.ts

src/structure/structure_props.ts

src/structure/structure_rectangular_orifice_free.ts

src/structure/structure_rectangular_orifice_submerged.ts

src/structure/structure_triangular_trunc_weir.ts

src/structure/structure_triangular_weir.ts

src/structure/structure_triangular_weir_broad.ts

src/structure/structure_vanlev_larinier.ts

src/structure/structure_vanlev_villemonte.ts

src/structure/structure_weir_cem88d.ts

src/structure/structure_weir_cem88v.ts

src/structure/structure_weir_cunge80.ts

src/structure/structure_weir_free.ts

src/structure/structure_weir_submerged.ts