[Feature]: Expose zstash commands via `import ztash`

### How will this affect the next version number?

New feature (increment MINOR version)

### Is your feature request related to a problem?

No problem.
I would like to use `zstash` within an existing python program. For e.g.
```python3
from zstash import create
create(kwargs_to_create)
```

Similarly, other functions of `zstash` such as `ls`, `extract`, `chgrp` etc. could also be exposed.

### Describe the solution you'd like

Making the methods such as `setup_create` in `create.py` take in optional arguments to allow passing the parser arguments as a dictionary. Doing so will allow `create` to be used directly from a calling python program.

There may be better more elegant solutions, but may need a redesign or refactor.

### Describe alternatives you've considered

_No response_

### Additional context

_No response_