prompt fix and evaluation code

[cbacode]

I am not sure about whether my changes in alphasql/database/utils.py could work, and the evaluation code is quite annoying so forgive me if I get anything wrong.

[BugMaker-Boyan]

We appreciate your contribution and would like to submit minimal feature modifications in a single PR. Specifically:

1. Please remove the code related to the evaluation.

2. Regarding the bug you identified with the excessively long example value text, we suggest you modify the SQL template statement at this location: Bug Code Line. Update the statement to:

   SELECT DISTINCT `{column_name}` FROM `{table_name}` WHERE `{column_name}` IS NOT NULL AND `{column_name}` != '' AND length(cast(`{column_name}` as text)) <= {max_example_length} LIMIT {max_num_examples};

   Additionally, add a default function parameter max_example_length with the value int = 100.

[cbacode]

Thanks for the detailed feedback!

Your response already provides a complete solution for the bug related to the excessively long example value text. Given that I currently lack the compute power to verify the proposed fix, I guess it makes more sense for you to finalize and merge this issue yourself.

If you are confident in my evaluation code fix, please just drop the changes to alphasql/database/utils.py from this PR.

Best wishes!