Add suggested gas fee to facilitate the gas cap limit feature.

[debendraoli]

Is your feature request related to a problem? Please describe.
We have to somehow facilitate the gas cap limit value to be used for gas protection feature. This is because gas-cap is mandatory now and will be hard to configure correctly.

Describe the solution you'd like
A cli something like suggest-gas-cap that can be directly copied and pasted on config.

Describe alternatives you've considered
N/A

Additional context
Consider per chain selection, --chain and --buffer x%.