Align more uniformely the table constraints and column options #2059
Description
Hi,
As it stands, the variants used for representing several table constraints or column options are different entries in different enums.
Once PRs like #2054 are merged, it will be possible to refactor the column options so that the sqlparser::ast::ColumnOption::ForeignKey variant becomes a simple tuple variant using the newly created ForeignKeyConstraint.
Is this desirable? If so, once the pending PRs are merged I can refactor those two enums to be more tightly aligned.
Best,
Luca