fix: Add check for whether account is deployed

[SilasZhr]

What?

This PR updates both simpleAccount.ts and gasLimit.ts with initCode issue.

Why?

• There is an issue when I want to send the first UO if I've deployed account proxy by calling senderCreator or AccountFactory.
• It always checks the nonce in EntryPoint in Here. But I think user should be able to use EntryPoint with deployed account.

How?

• check the account code instead of ctx.op.nonce when setting initCode for UO
• check initCode length before getting factory address from initCode, and return zero for CreationGas if initCode is 0x

Testing?

Passed