Update `show_versions` to have command and snaphu info

[scottstanie]

We should add a dolphin --show-versions similar to the rio --show-versions. The basic function now, but you need to do:

$ python -c 'import dolphin; print(dolphin.show_versions())'
dolphin/isce info:
     dolphin: 0.10.0
 opera_utils: 0.2.0.post1.dev4+g3e48d74
       isce3: 0.17.1
       tophu: 0.2.0

System:
      python: 3.11.6 | packaged by conda-forge | (main, Oct  3 2023, 10:37:07) [Clang 15.0.7 ]
  executable: /Users/staniewi/miniconda3/envs/mapping-311/bin/python
     machine: macOS-13.6.4-arm64-arm-64bit

Python deps:
       numpy: 1.26.2
       numba: 0.58.1
         jax: 0.4.21
  osgeo.gdal: 3.7.3
        h5py: 3.10.0
 ruamel_yaml: None
    pydantic: 2.5.2
  setuptools: 68.2.2
optional GPU info:
gpu_is_available() = False
         jax: 0.4.21
gpu_is_available: False
None

• [ ] There's a None printed at the end. confusing to me
• [ ] the new snaphu dep is missing