get https://api-sandbox.thisisbud.com/aggregations/v2/buckets/
Retrieve the definition of a bucket, and retrieve helper metadata which can be used
for presenting options to customers.
For example, the metadata.category_lookup property can be used to show a dialog box
to customers for the customers to be able to correct their transactions (using the
Correct Transaction Categories V2),
and using the correct category_l1/category_l2 pair.