Fix: always keep the nonce of existing txs

[katspaugh]

What it solves

Solves a bug with delegated txs:

• A delegate address creates a tx with nonce N
• An actual owner address signs it
• Instead of signing the tx N, it creates another tx with a nonce N + 1

How this PR fixes it

The tx confirmation flow will now always use the original transaction nonce and won't update it to the recommended nonce.

How to test it

• Create an unsigned tx using MetaMask institutional or a delegate address.
• Sign it with an owner key
• Observe that it signed the original tx and not created a new tx

[github-actions]

Branch preview

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https://fix_nonce--walletweb.review-wallet-web.5afe.dev

[github-actions]

ESLint Summary View Full Report

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Type	Occurrences	Fixable
Errors	0	0
Warnings	0	0
Ignored	0	N/A

• Result: ✅ success
• Annotations: 0 total

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^{Report generated by eslint-plus-action}

[liliya-soroka]

The fix for the unsigned txs is verified. The same nonce is suggested during signing as was used for the tx creation

[liliya-soroka]

Quick check was done for :

1. reject tx
2. replace tx
3. create new tx ( send token, send NFT, safe apps tx)
4. spending limit tx( module tx)
5. recommended nonce option