[speed] Improve execution time for small orders

[anxolin]

Potential ideas:

• Detect when gas price changes might have a big impact on the execution
• React to the above (preventing the user from creating the order in some cases and allowing to place anyway knowing it might be delayed), alternatively or in addition, make sure if the user places the order we recommend adding some extra buffer for the slippage tolerance
• Potentially, the smart slippage calculation should take volume into account
• Good to have: estimate the expected volatility in gas prices for the next 30min and enhance the smart slippage calculations

After the improvements, we should monitor the SLI dashboard and focus on understanding the outliers.

[elena-zh]

Hey @anxolin , should #4316 task be closed then?