Remove deprecated properties, networkChanged event, and offline send() net_version support

[jiexi]

This PR removes properties that are not officially documented and should not have been exposed in the first place. It also removes support for the networkChange event and offline net_version resolution which will allow us to remove the last remaining chunk of networkId usage in Extension. These have all been properly deprecated, the most recent deprecations being 180 days old now.

Removes the following:

• window.ethereum.chainId
• window.ethereum.networkVersion
• window.ethereum.selectedAddress
• networkChanged event
• offline net_version support in window.ethereum.send()

See: https://github.com/MetaMask/MetaMask-planning/issues/2195 See: https://github.com/MetaMask/metamask-improvement-proposals/discussions/23 See: https://github.com/MetaMask/MetaMask-planning/issues/2176 See: https://github.com/MetaMask/metamask-extension/pull/23375

Before

After

[shanejonas]

Total sidebar here but

null {id: undefined, jsonrpe: '2.0', result: '100'}

Wow looks like send doesnt generate an ID like how we have request set up. I do like that send leaves it up to the client to deal with the ID.