Standardise function hover

[gnikit]

Hover over functions can produce vastly different results depending on how the function is written.
Hover results will be different depending on whether the function type and the function result are present.
The output should be standardised regardless of how the function is written.

! simple function
function fun1(arg)
    integer, intent(in) :: arg
    integer :: fun1
end function fun1

! function with type on definition, implied result
integer function fun2(arg)
    integer, intent(in) :: arg
end function fun2

! function with return
function fun3(arg) result(retval)
    integer, intent(in) :: arg
    integer :: retval
end function fun3

! function with type on definition and return
integer function fun4(arg) result(retval)
    integer, intent(in) :: arg
end function fun4