feat: Add better printing to the output of `search_content()`

[toph-allen]

It's unwieldy to see the entire output of the content search printed as a list of lists. Modifying the list so that every item has a class with a nicer print method would improve this.

[jonkeane]

Modifying the list so that every item has a class with a nicer print method would improve this.

This is one way, another is that the list that contains them has the pretty print method, so you don't get the base list printing cruft

[toph-allen]

Prior art reference from the newer integrations S3 object — still has "list cruft" in the print output but this also allows single integration objects to be printed.

connectapi/R/integrations.R

Lines 164 to 169 in dc55d83

	print.connect_integration <- function(x, ...) {
	cat("Integration:", x$name, "\n")
	cat("GUID:", x$guid, "\n")
	cat("Template:", x$template, "\n")
	invisible(x)
	}