refactor: rename lambdas to use camelCase instead of snake_case

[andreabadesso]

I know this project style is to use snake case for lambda names but AWS translates to camel case replacing each underscore with Underscore for some internal names (e.g. policy statement name) this makes the name longer and easier to hit the limit, failing the deploy.

I think we should create new lambdas with camel case to avoid these issues.

Originally posted by @r4mmer in #189 (comment)