feat: break up allowance approval flow in prep for permit2

[woodenfurniture]

Description

Breaks token allowance approval UI components into reusable ones in prep for permit2 UI flow.

• Adds default "exact" allowance state per conversation with product (previously this was only the case for LiFi trades).
• Copy for allowance reset is now "allowance reset", not "approval reset"
• Copy for allowance approval is not "allowance approval", not "approval"
• Code renaming to correspond to the above
• Combine allowance reset and allowance approval steps into a single allowance step. This is in preparation for permit2 which will require similar combining of UX to mitigate "CVS receipt" UX hell
• includes placeholder states for permit2 flow which will follow on from this PR

Issue (if applicable)

progresses #7648

Risk

High Risk PRs Require 2 approvals

This is a high risk change because it modifies the state management of trades and majorly refactors the UI associated with allowance approvals.

What protocols, transaction types, wallets or contract interactions might be affected by this PR?

All trades, especially those with token allowance approvals.

Testing

• trades on all chains
• trades without allowance approvals
• trades with allowance approvals
• trades with USDT allowance reset and approval

Engineering

Operations

• 🏁 My feature is behind a flag and doesn't require operations testing (yet)

Screenshots (if applicable)

No allowance approval

With allowance approval

With USDT allowance reset and approval