feat: display a warning if the output amount changes on the confirm swap page

[Ikari-Shinji-re]

Summary

If the user proceeds to the confirm swap page and the output amount differs from the previous quote response, or if the output amount changes when the quote refreshes on the confirm swap page and these changes meet certain criteria, we should display an appropriate warning to prevent potential loss for the user:

usdInput >= 1000 and percentageChange >= 1
usdInput >= 500 and percentageChange >= 2

In this pull request, I also removed some unused code that was previously needed for route update situations. Additionally, I worked on refactoring and cleaning up how we retrieve the USD value of the source or destination token.

How did you test this change?

To test these changes, it’s best to manipulate the quote response in the confirm swap flow, as the real scenario may not occur frequently.

Make this changes to generateQuoteWarnings function :

export function generateQuoteWarnings(params: {
  previousQuote?: SelectedQuote;
  currentQuote: SelectedQuote;
  findToken: FindToken;
  userSlippage: number;
}): QuoteWarning | null {
  const { previousQuote, findToken, userSlippage } = params;
  const currentQuote: SelectedQuote = {
    ...params.currentQuote,
    outputAmount: String(0.97 * parseFloat(previousQuote?.outputAmount ?? '0')),
  };
  ///////
  //////
 }

Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• Implemented a user interface (UI) change, referencing our Figma design to ensure pixel-perfect precision.

[mikasackermn]

LGTM