Add reference data models and seed data for incoterms, invoice types, material types, payment methods, pedimento codes, pedimento regimens, sectors, states, transport modes, transport types, and valuation methods

- Implemented SQLAlchemy models for incoterms, invoice types, material types, payment methods, pedimento codes, pedimento regimens, sectors, states, transport modes, transport types, and valuation methods.
- Added seed data for each reference data model to populate the database with initial values.
- Ensured primary key constraints and appropriate data types for each model.
- Established relationships where necessary, particularly in pedimento codes and regimens.

models.py

@@ -86,38 +86,6 @@ class Gempresa(Base):
 
     gempresa_sucursales: Mapped[List['GempresaSucursales']] = relationship('GempresaSucursales', uselist=True, back_populates='gempresa')
 
-class Gtiposfactura(Base):
-    __tablename__ = 'gtiposfactura'
-    __table_args__ = (
-        PrimaryKeyConstraint('clave', name='gtf_pkclave'),
-    )
-
-    clave = mapped_column(String(5))
-    descripcion = mapped_column(String(50))
-    observacion = mapped_column(String(500))
-    tipo_origen = mapped_column(String(15))
-
-
-class Gtiposmoneda(Base):
-    __tablename__ = 'gtiposmoneda'
-    __table_args__ = (
-        PrimaryKeyConstraint('clave', name='tipmon_pkclave'),
-    )
-
-    clave = mapped_column(String(3))
-    moneda = mapped_column(String(15))
-    descpais = mapped_column(String(50))
-
-
-class Gtipotransportes(Base):
-    __tablename__ = 'gtipotransportes'
-    __table_args__ = (
-        PrimaryKeyConstraint('clavetransporte', name='gtipotransportes_pkey'),
-    )
-
-    clavetransporte = mapped_column(String(2))
-    descripcion = mapped_column(String(100), nullable=False)
-
 t_gempresa_certificacion = Table(
     'gempresa_certificacion', metadata,
     Column('id_empresa', String(3), nullable=False),