Number formats

[ldavies99]

Is your feature request related to a problem? Please describe.
The data contained in the gptables tables are in a 'general' format when I want the data to be in a 'number' format.

Describe the solution you'd like
A way to set the number format of the data in the tables.

Additional context
I believe this could be done by adding set_number_format() to the available additional formatting options.

[ldavies99]

I've tried to use set_number_format() in additional formatting but have found that it is not possible when there are mixed data types in the column.

[rowanhemsi]

May require a different way of handling shorthand in order to support this