Allow users to define the cardinality threshold for dictionary reads #24113

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