fix: cassandra vault list with marker and limit

- fix marker to be '' instead of '0' when the marker isnt specified
vaultid needs to be set to something if its None or not, thats because there's a placehaolder in the format string..

CQL_GET_ALL_VAULTS:
```python
CQL_GET_ALL_VAULTS = '''
    SELECT vaultid
    FROM vaults
    WHERE projectid = %(projectid)s
    AND vaultid >= %(vaultid)s
    ORDER BY vaultid
    LIMIT %(limit)s
'''
```

the vaultid>= part is where the marker comes in.

I could change it to

```python
vaultid = marker or ''
```