Allow to natively use cat_where during dev

[ColinFay]

First of all, nice work!

How would you feel about natively add a wrapper around {whereami} for dev logs?

I've been using whereami::cat_where() for logging from which file the event is fired during dev.

It definitely help to find back where to go for debugging.

So for example log_event("Hello World") would output

|#1|EVENT|Hello World|FIRED|
|#1|WHERE|observeEvent(...) at R/mod_bla#123|

https://github.com/yonicd/whereami

ping @yonicd