fix: display the response error message instead of the axios error

[Ikari-Shinji-re]

Summary

When a user tries to make a swap and the server cannot create the transaction, the API returns an HTTP error status along with an error message in the response body. Previously, we incorrectly displayed the HTTP library (Axios) error instead of the server-provided error message.

Fixes # (issue)

• Updated the prettifyErrorMessage helper to check whether the error is an Axios error.
• If the error is an Axios error, we now return the error field from the response object instead of the default Axios error message.

How did you test this change?

Override the /tx/create response with the following:

status code: 400

{
  "ok": false,
  "error": "failed for test",
  "errorCode": 1234,
  "traceId": 123456,
  "transaction": null
}

Steps:

1. Select a route for a swap.
2. Start the swap flow.

Expected result:
The displayed error message should be "failed for test" from the response object, instead of the Axios error mess

You can also verify this by trying this route on XO Swap:
/?fromBlockchain=ARBITRUM&fromToken=USDT--0xfd086bc7cd5c481dcc9c85ebe478a1c0b69fcbb9&toBlockchain=TRON&toToken=USDT--TR7NHqjeKQxGTCi8q8ZY4pL8otSzgjLj6t&fromAmount=10

• Test A
• Test B

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.

[nikaaru]

LGTM