Adjust timeouts to timestamps on Arbitrum

[taleldayekh]

Description

Confirmation blocks might not be needed on rollups and therefore pointless to wait 5 blocks after a transaction.

Acceptance criteria

• See if client works with confirmation block 0 or 1.

Tasks

• [ ]

[andrevmatos]

As per #2915 (comment) , the current value should be fine on the clients, except on Metamask outdated blockNumber caching; but for that, we may need to tweak other parameters on fast networks like Arbitrum, instead of confirmationBlocks. This parameter can be reduced to 2 or 1 on clients which are confident they can keep up to date with current blocks, but 5 usually is safer, and for bigger delays on dApp with Metamask, we need to tweak the timeouts instead.
I think we can keep this issue open, and edit it to better describe the tweaks needed on the timeouts on the specific network speed/behavior.