Make pre-created FILE_FORMAT object optional

[aaronsteers]

Is your feature request related to a problem? Please describe.

This is not a bug but would expedite and streamline adoption for new useres.

Describe the solution you'd like

By making FILE_FORMAT optional, we can default to an inline CSV file format and not require pre-creating a FILE_FORMAT object in Snowflake.

Describe alternatives you've considered

The alternative I'm aware of it to create the FILE_FORMAT object manually. This is not especially conducive to trainings and other processes where we want to minimize pre-work and prereqs.

Additional context

Sample code below uses an inline format expression as in the example from Snowflake's docs here.

COPY INTO <dest_table> (<col_list>)
FROM <stage>
FILE_FORMAT = (
    TYPE = CSV
    EMPTY_FIELD_AS_NULL = FALSE
    FIELD_OPTIONALLY_ENCLOSED_BY = '"'
)