Removed wrong or deprecated networks, added new testnets

[StErMi]

Networks removed

• Removed ethereum ropsten testnet: not supported anymore, give error
• Removed ethereum rinkeby testnet: not supported anymore, give error
• Removed ethereum goerli testnet: deprecated and readonly. Replaced by sepolia/holesky ethereum
• Removed ethereum kovan testnet: not supported anymore, give error
• Removed optimism kovan testnet: not supported anymore, give error
• Removed arbitrum testnet: not supported anymore, give error
• Removed base goerli testnet: not supported anymore, give error

Networks added

• holesky ethereum testnet
• sepolia optimism testnet
• sepolia arbitrum testnet

Note:

• goerli optimism has not been added because it's deprecated already

[krzkaczor]

Thank you!