Refactoring for EQP training

[dreamer2368]

• Navier-Stokes advection operators are changed to HyperReductionIntegrator:
  • IncompressibleInviscidFluxNLFIntegrator
  • DGLaxFriedrichsFluxIntegrator
• For ROMBuildingLevel::COMPONENT, now the routines for ROM elements are factored out by their nonlinearity types: linear, tensor, or EQP.
  • Linear ROM elements require train_rom, build_rom stages.
  • Tensor ROM elements also require train_rom, and build_rom stages.
  • EQP ROM elements require train_rom and train_eqp stages.
  • At single_run with ROM, linear ROM elements are loaded and assembled by default, and nonlinear ROM elements are loaded and assembled according to the specified input (tensor or eqp)