Feature ORM for CCIP in-db prices

[matYang]

Add ORM and corresponding tables for CCIP gas prices and token pries

[krehermann]

lgtm to the small nit about the test

[jmank88]

I think we typically let the database set this field instead of passing it explicitly.

[matYang]

my understanding is there isn't a single best practice when it comes to passing in timestamp v.s DB default, in this case:

1. DB default makes tests tricky, the get logic is dependent on sorting by timestamp, timestamp during tests is not increasing reliably
2. delete logic is based on application's timestamp, it'd be more consistent for created_at to be based on application timestamp too

[reductionista]

I think of best practice as using db clock for both inserts and deletes rather than golang clock.

now() is an alias for transaction_timestamp() which returns the start time of the current transaction. That does have issues with tests, because we run all tests within a single transaction. However, I think any of the following should probably work without issues: statement_timestamp(), clock_timestamp(), or just TIMESTAMP 'now' https://www.postgresql.org/docs/current/functions-datetime.html#FUNCTIONS-DATETIME-CURRENT

[cl-sonarqube-production]

Quality Gate failed

Failed conditions
2 New Blocker Issues (required ≤ 0)

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