add conda lockfile backup and restore script

[asmacdo]

I needed this functionality for our deployment. I know some previous work has taken place on this, so I'm not certain if this is the direction upstream would like to go-- but if so I think this should ultimately be split into 3 PRs.

• conda-store: When using the conda-store API we use the conda API client which needed a small extension for the endpoints we use here.
• nebari script: Pretty much what is here with the API extensions removed
• nebari-docs: Manual backup/restore docs to use this script.

Reference Issues or PRs

Related to conda-incubator/conda-store#889 (implements backup, and restore, but not archive)

What does this implement/fix?

backup retrieves a conda-lock file per environment in conda-store.
restore builds an environment per conda-lock file. (skips rebuilding existing by default)

TODO Documentation

Heres the docs for using this with our deployment, I can add this to nebari-docs in a separate PR if this feature is desired.

## Conda Store                                                                                                                             
                                                                                                                                           
Use the `conda-store-lifecycle.py` script to trigger backups and restores.                                                                 
                                                                                                                                           
You will need the following env vars:                                                                                                      
                                                                                                                                           
 - `CONDA_STORE_TOKEN`: see below                                                                                                          
 - `CONDA_STORE_URL`: (ie "https://hub-staging.dandiarchive.org/conda-store")                                                              
                                                                                                                                           
To get a CONDA_STORE_TOKEN:                                                                                                                
 - go to [conda-store admin ui](https://hub-staging.dandiarchive.org/conda-store/admin/) logged in as a user with the "superadmin" Keycloak
 - click "User", and then "Create Token".                                                                                                  
                                                                                                                                           
Execute from this dir:                                                                                                                     
                                                                                                                                           
```bash                                                                                                                                    
cd ops/backup                                                                                                                              
./conda-store-lifecycle.py backup --backup-dir hub-staging/conda/                                                                          

And to restore (idempotent, skips existing dirs)

./conda-store-lifecycle.py restore --backup-dir hub-staging/conda/                                                                         

_Put a `x` in the boxes that apply_

- [ ] Bug fix (non-breaking change which fixes an issue)
- [X] New feature (non-breaking change which adds a feature)
- [ ] Breaking change (fix or feature that would cause existing features not to work as expected)
- [ ] Documentation Update
- [ ] Code style update (formatting, renaming)
- [ ] Refactoring (no functional changes, no API changes)
- [ ] Build related changes
- [X] Other (please describe): Add a new script

## Documentation

- [ ] For new features or enhancements, a corresponding PR has been opened in the [documentation repository](https://github.com/nebari-dev/nebari-docs) (if applicable)
  - Link to docs PR:

## Testing

- [ ] Did you test the pull request locally?
- [ ] Did you add new tests?

## How to test this PR?

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