Update bundler logic for user operation Nonce

[octavei]

Usually, we will check the nonce value in the transaction pool, which ensures normal transactions on our chain. Why in op, we don't do this kind of operation ?

[zsluedem]

https://github.com/Vid201/aa-bundler/discussions/163#discussioncomment-6476055 @octavei Makes a very good point here. For some circumstances, users want to submit several userOps at a time. Current bundler could not handle a situation like this.

[Vid201]

Check: https://eips.ethereum.org/EIPS/eip-4337#semi-abstracted-nonce-support