dApps - improve eth_signTransaction handling

[virginiabalducci]

Description

The eth_signTransaction is not supported by the Status App.

Metrics

Related to #16912

Some metrics triggers for the eth_signTransaction method:

• an eth_signTransaction request is received -> metric triggers correctly upon receiving the request
• an eth_signTransaction request is accepted -> since the Status desktop app does not support accepting this type of transaction, it is automatically rejected when tried to accept it.
• an eth_signTransaction request is rejected -> metric triggers correctly upon rejecting

Acceptance Criteria

This AC cannot be triggered because the Status app will always reject these transactions.

Given a sign/transaction request is accepted
Then a new dapps-sign event is sent and the following properties are filled
flow=sign_accepted
connector - wallet_connect or browser_connect
method - signing method: eth_signTransaction
chainId - chain id
dapp - dapp URL

When trying to accept this, the metric that triggers is the reject one, which is correct.

Given a sign/transaction request is rejected
Then a new dapps-sign event is sent and the following properties are filled
flow=sign_rejected
connector - wallet_connect or browser_connect
method - signing method eth_signTransaction
chainId - chain id
dapp - dapp URL

You can test at https://se-sdk-dapp.vercel.app/

It's rejected when trying to sign the request using the eth_signTransaction method, and an error message is displayed. We should find a better way to handle the error, specifying the method and the dApp used. It would be nice to have a better error message since right now, we see the following:

error:
Rejecting due to error

https://eu.mixpanel.com/project/3350627/view/3857659/app/events#kG8M2voqqmE4