Adjust Market Order Logic When Limit Orders Are Disabled

[nlordell]

This PR adjusts the order classification logic.

Specifically, when limit orders were disabled, it was possible to create market orders with a 0-fee (as the 0-fee would cause it to skip the get_quote_and_check_fee fee check but disabled limit orders make the order be considered a market order).

@fedgiac and I already applied a hotfix in production, this PR adds the fix to main as
well. This is not urgent (as limit orders are enabled in staging, so it is not possible to create 0-fee market orders ATM).

Additionally, this PR also:

• restores the behaviour of out-of-market orders being flagged as liquidity orders
• only stores quotes at order creation if an existing quote wasn't found. This is to avoid orders that are created with a specific quote ID getting a different one.

Test Plan

Changed the test that checks 0-fee market orders error validation when limit orders are disabled, and added a new test to prevent regressions of the liquidity classification for out-of market orders.

[nlordell]

Merging this with a single approval as @fedgiac reviewed the changes with me when creating the v2.80.2 release and this is an important change for next week.