Add broker and ewallet schema

[wongjingping]

Add broker and ewallet schema (and data):

• broker has camelCased table/column names and a standard prefix for all column names from the same table. broker also avoids the user of FOREIGN KEY/REFERENCES
• ewallet contains a transactional tech/e-commerce company's schema. ewallet has a schema name consumer_div. prepended to each table's name, and uses REFERENCES
  Together with the earlier 2 schema:
• car_dealership has a sales-ish inventory schema that mimic a sales function in a company
• derm_treatment mimics a pharmaceutical company tracking clinical trials and various experimental treatments. It contains cohort-style data in a wide-format

We also sparsified the descriptions for the car_dealership schema to avoid excessively long contexts with redundant information.
Added tests to check for the number of columns for each schema.

Did a test on the number of tokens (using codellama's tokenizer) required to tokenize the sql (without the insert statements, and not using the json):

Schema	Num_tokens
broker	715
car_dealership	867
derm_treatment	1218
ewallet	1484

And here are the number of tokens required to tokenize the glossary:

Schema	Num_tokens
broker	172
car_dealership	265
derm_treatment	365
ewallet	325

[rishsriv]

Amazing. Thank you!