Get function name from function

[ldemailly]

first/rest/defun in #210 / #221 allows extraction of functions args/body and recreation - except to get the name

as side note, str(func) prints really weird stuff

func xor(a,b) {a^b}
str(xor)
"{[0x14000452930 0x14000452960] 0x140004528c8 func (a,b){a^b} 0x1400042dbe0 0x140000dccc0 false false}"

note we fixed it for gofuncs for examples/functions_list.gr such as str(eval(name)) prints the help we can probably do same or have
some inspect or map with the name if any (issue being if passing a lambda)

[ldemailly]

func funname(fn) {regexp("func ([^(]+)", format(fn), true)[1]}

this works, meanwhile