Consider the usage of staticcall for read only cross-contract calls

[sangier]

Staticcall can be useful for functions where only a return value is desired and state changes are unwanted. It add an extra layer of safety since it will revert if the contract called causes a state change and can save some gas.

Food for thoughts:

• https://github.com/ethereum/EIPs/blob/master/EIPS/eip-214.md
• https://www.rareskills.io/post/solidity-staticcall#:~:text=Staticcall%20is%20like%20a%20regular,in%20solidity%20function%20named%20staticcall.

1. More investigation is needed.
2. The snippets of code where it can be applied should be identified.