Add to and to_columns to ColumnLevelConstraint and ModelLevelConstraint contracts

[MichelleArk]

Housekeeping

• I am a maintainer of dbt-common

Short description

as part of dbt-labs/dbt-core#8062, we will need to extend these contracts to optionally include to and to_columns fields.

Acceptance criteria

ColumnLevelConstraints and ModelLevelConstraints have optional to and to_column contracts.

Suggested Tests

N/A

Impact to Other Teams

N/A

Will backports be required?

nope

Context

No response