(cherry picked from commit 2b53f80392169b047fc21cfaba43c084ea45a5f2)

Change to `info styles [all|atom|pair|compute|...]`.
By default, `info styles` will print all styles.

Adds the ability to list all available styles in LAMMPS with:

```
info styles
```

Each style can also be printed separately using one of the following:

```
info atom_styles
info integrate_styles
info minimize_styles
info pair_styles
info bond_styles
info angle_styles
info dihedral_styles
info improper_styles
info kspace_styles
info fix_styles
info compute_styles
info region_styles
info dump_styles
```

(cherry picked from commit eba3ad9abb37b53fc2f79449bb8eada8f0ec526a)

individual computes do not need to set vector/array to NULL. reordering fixes to silence compiler warnings

(cherry picked from commit f30232b41ed2ad0db8fdb90155da01dadd9e5574)