Provide more informative warning when argument vectors are recycled

[matt-dray]

Let the user know about mismatches in input-vector lengths. Related to #28.

Use {cli} and ... approach as per #50 to accept the length of any number of arguments, check them for length and report back to the user. Will likely need to be a tryCatch() to suppress the default R message and replace with our own.

We're doing this to provide a nicer user-interface. The default warning is terse:

> 1:2 + 1:3
[1] 2 4 4
Warning message:
In 1:2 + 1:3 :
  longer object length is not a multiple of shorter object length

And it prints multiple times with multiple violations:

> 1:2 + 1:3 + 1:4
[1] 3 6 7 6
Warning messages:
1: In 1:2 + 1:3 :
  longer object length is not a multiple of shorter object length
2: In 1:2 + 1:3 + 1:4 :
  longer object length is not a multiple of shorter object length

It's probably fine not to warn when one of the arguments is length 1, though. There's no warning for this in base either.

> 1 + 1:2
[1] 2 3