Support S3 classes

[mvankessel-EMC]

Implement support to be able to detect and investigate S3 classes.

[mvankessel-EMC]

The S3 constructor should be picked up by PaRe, and report this somehow.

# S3: structure
chell <- structure(list(name = "Chell", age = 29), class = "Person")

# S3: class
morgan <- list(name = "Morgan", age = 28)
class(morgan) <- "Person"

The following S3 method definitions should already be picked up:

Overload print:

print.person <- function(x, ...) {
  glue::glue("{x$name} is {x$age} years old.")
}

Create custom generic doStuff:

doStuff <- function(x) {
  UseMethod("doStuff")
}

doStuff.person <- function(x) {
  glue::glue("{x$name} does stuff.")
}

doStuff and doStuff.person should already be picked up seperately.