Improve compatibilities between runtime options

[MaxThevenet]

Currently, there are a number of options in HiPACE++ that cannot be used together. This issue aims at listing them in order of priority (top = highest priority), so they can be addressed.

• Explicit solver and ion motion (see Explicit solver with Ion motion #737)
• Explicit solver and mesh refinement (see Mesh Refinement with Explicit Solver #835)
• Explicit solver and high temperature (see fix reset of initial plasma particle momentum #637 and Directly deposit source terms for the explicit solver #805)
• Laser envelope and SI units (see Laser envelope: static laser #641)

[MaxThevenet]

Great work @AlexanderSinn!! That's a large issue that we can close. All is ready for explicit to be the default now :).