Allow setting a default number format

[jonahgreenthal]

Redash supports a default date format and a default time format (in Settings > General). It would be good to support default number formats too.

My use case: The overwhelming majority of numbers I work with are integers, and I would prefer that they be formatted without thousands separators. For example, I want 12345. However, Redash defaults to formatting with commas as thousands and showing two decimal places (e.g., 12,345.00). I'd love to change the setting all at once rather than editing the visualization for every query, column-by-column.