Core htmx internals Tests

• appendParam can process objects0ms ‣

  var param = htmx._('appendParam')('a=b', 'jim', 'foo')
  should.equal(param, 'a=b&jim=foo')
  param = htmx._('appendParam')('a=b', 'jim', '{"foo":"bar"}')
  should.equal(param, 'a=b&jim=%7B%22foo%22%3A%22bar%22%7D')
  param = htmx._('appendParam')('a=b', 'jim', { foo: 'bar' })
  should.equal(param, 'a=b&jim=%7B%22foo%22%3A%22bar%22%7D')