Reduce Round Change timeout

[GalRogozinski]

Description

Currently we change round every 2 seconds while we observe latency that is much lower (~300 ms MAX)
We can consider lowering the timeout to ensure a duty gets in on time.
We can also have different timeout for different duties.

[y0sher]

I think this is mostly relevant in Proposer duties, where a single round change of 2s can make you miss the block. Potentially this could improve other duties as well as round changes will be resolved faster.

[GalRogozinski]

Before we reduce round change we need to do ssvlabs/ssv-spec#371 and get empirical data again