Allow users to define the cardinality threshold for dictionary reads

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

_No response_

### Describe the solution you'd like

Add a config option to set a cardinality threshold, so columns above it are read as regular strings instead of dictionaries.

for example
```
SET datafusion.parquet.dict_threshold = 0.2 # dataset must have less than 20% unqiue values
```
or
```
SET datafusion.parquet.dict_threshold = 200 # 200 unique values max
```

we can support both but im leaning towards supporting a percentage threshold.

### Describe alternatives you've considered

_No response_

### Additional context

#24111