Make use of macros for defining swipe-related items

[diego-plan9]

Related to #26

As the number of events increases, there are some places in the codebase which might benefit from using macros to declare them: for example, the list of arguments related to swipe in the Ops struct for clap.

We should evaluate introducing some macros to alleviate the effort and make it less error-prone, reduce repetition and increase the readability overall.