Nit: different lib names and packages names

[Henry-E]

In the cargo.toml, the package name is openbook-twap and the lib name is openbook_twap.

It's not a big deal but solana-verify is very specific about using the lib name. Which makes writing scripts to deploy annoying since you have to switch between lib and package name or know which needs to be used in what scenario. If they're both the same then there's no thought required.

It's an easy change but I don't want to break anything upstream that imports openbook_twap as a lib. So would like to see it done but it's not really a priority.