Add soliton potential for Bondi accretion problem

[sandy0216]

No description provided.

[hsinhaoHHuang]

@sandy0216 Thanks for this pull request. It is a really interesting test problem.
I have reviewed it. Please let me know if my comments are unclear or if I got something wrong.

Besides the inline comments, I also have some comments here:

1. Please also update the example/test_problem/Hydro/Bondi/README to describe the new soliton-potential model.
2. I am not familiar with this test problem. I am wondering whether there is a way to know if the simulations run well, e.g., by comparing them to the analytical solution or analyzing the accretion rate. Or what should I expect to see the results of the new soliton-potential model?
3. I am curious whether the Bondi_Soliton model is also a kind of hydrostatic equilibrium. If it is, why is it not implemented as a new Bondi_HSE_Mode? If it is not, what is its main difference to the three models of HSE_Mode?
4. In SetGridIC(), there are 6 types of initial conditions: Bondi_HSE={1,2,3}, Bondi_Init=1, Bondi_Soliton=1, and the uniform. They are mutually exclusive, and there is a built-in order to decide which is adopted. For example, if the user sets Bondi_HSE=1; Bondi_Init=1; Bondi_Soliton=1;, it will only run Bondi_HSE=1, and the other two options will not actually be used. Users may not be aware of this. We have better tell the users about these rules in Input__TestProb and also check the input parameters and reset some of them to 0 in SetParameter() if there are conflicts. It would be better if we could make the dependency of parameters clear, like which parameter will be useless if which other parameter is off.
5. For Bondi_Init mode, it requires an input table. We should provide a default one in example/test_problem/Hydro/Bondi/.
6. The attached plotting scripts in example/test_problem/Hydro/Bondi/ seem outdated.
   • In plot_profile.gpt, we don't need ../../ in FILE_BONDI and DUMP_TABLE.
   • In plot_diagonal.gpt, the indices of some columns are wrong if there is the dual energy. The Mach number is 17 and the pressure is 14 now.

72c72
<         u (abs($4-CENTER)*3**0.5):16 w p pt 6 lc 6 tit 'Simulation' \
---
>         u (abs($4-CENTER)*3**0.5):17 w p pt 6 lc 6 tit 'Simulation' \
82c82
<         u (abs($4-CENTER)*3**0.5):13 w p pt 6 lc 6 tit 'Simulation' \
---
>         u (abs($4-CENTER)*3**0.5):14 w p pt 6 lc 6 tit 'Simulation' \

7. GAMER has its own unique coding style. Although there is no official styling guide, we can try to follow a consistent code format. Therefore, please check again that the vertical alignment, the 3 spaces indentation, the comments, the variable names, and the spaces in if, for, etc. are consistent with elsewhere.
   • We don't want the trailing space in the .cpp file. We can check it by the command grep -r -n ' $' src/ in the terminal:

src/TestProblem/Hydro/Bondi/ExtAcc_Bondi.cpp:79:                
src/TestProblem/Hydro/Bondi/ExtAcc_Bondi.cpp:81:      } 
src/TestProblem/Hydro/Bondi/Flu_ResetByUser_Bondi.cpp:54:   if ( !Bondi_void ) 
src/TestProblem/Hydro/Bondi/Init_TestProb_Hydro_Bondi.cpp:412:         
src/TestProblem/Hydro/Bondi/Init_TestProb_Hydro_Bondi.cpp:433:      
src/TestProblem/Hydro/Bondi/Init_TestProb_Hydro_Bondi.cpp:599:      
src/TestProblem/Hydro/Bondi/Init_TestProb_Hydro_Bondi.cpp:627:   } 
src/TestProblem/Hydro/Bondi/Init_TestProb_Hydro_Bondi.cpp:764:   
src/TestProblem/Hydro/Bondi/Init_TestProb_Hydro_Bondi.cpp:781:   
src/TestProblem/Hydro/Bondi/Init_TestProb_Hydro_Bondi.cpp:804:

[hyschive]

• Most comments raised by @hsinhaoHHuang have been adddressed by this follow-up PR.
• Remaining tasks have been recorded here. @sandy0216 Please handle it when you have time.

[hyschive]

@sandy0216 @hsinhaoHHuang Looks good. Thank you both for the excellent contribution and thorough review!