feat(`forge create / cast send`): add `--gas-estimate-multiplier` flag

[mattsse]

Component

Forge

Describe the feature you would like

For certain networks, gas(price) may be incorrectly estimated, resulting in transactions that are underpriced:

#1703

in forge create we use the default Provider::{estimate_gas,get_gas_price} functions to fill the transactions, if they're not provided via cli arguments

it would be useful to scale these estimates percentage-wise, perhaps --scale-gas-limit 20 to use a 1.2 multiplier for the gas limit.

Additional context

No response

[shawnharmsen]

I'd like to take a stab at this, will update with pr soon

[mattsse]

awesome! keep 'em coming!