Optimize id matching

[ypconstante]

Today the id matching goes through all node attributes trying to find an exact id, even after checking an id attribute with a different value.

This PR changes the check find the first attribute id instead of keep checking the remaining attributes.

When using attributes as lists performance is basically the same, but for attributes as maps performance improved significantly.
For both cases the memory usage is reduced.

##### With input bench #####
Name                               ips        average  deviation         median         99th %
attributes_as_maps (pr)         158.48        6.31 ms    ±23.60%        6.19 ms        9.87 ms
attributes_as_lists (pr)        158.37        6.31 ms    ±25.44%        6.15 ms       10.31 ms
attributes_as_lists             157.35        6.36 ms    ±22.13%        6.25 ms        9.67 ms
attributes_as_maps              130.97        7.64 ms    ±21.17%        7.52 ms       11.90 ms

Comparison:
attributes_as_maps (pr)         158.48
attributes_as_lists (pr)        158.37 - 1.00x slower +0.00458 ms
attributes_as_lists             157.35 - 1.01x slower +0.0453 ms
attributes_as_maps              130.97 - 1.21x slower +1.33 ms

Memory usage statistics:

Name                        Memory usage
attributes_as_maps (pr)          2.89 MB
attributes_as_lists (pr)         2.89 MB - 1.00x memory usage -0.00183 MB
attributes_as_lists              3.07 MB - 1.06x memory usage +0.182 MB
attributes_as_maps               3.86 MB - 1.33x memory usage +0.97 MB

read_file = fn name ->
  __ENV__.file
  |> Path.dirname()
  |> Path.join(name)
  |> File.read!()
end

html_input = read_file.("medium.html")

[{"html", _, _} = html_attributes_as_lists | _] = Floki.parse_document!(html_input)
[{"html", _, _} = html_attributes_as_maps | _] = Floki.parse_document!(html_input, attributes_as_maps: true)

Benchee.run(
  %{
    "attributes_as_lists" => fn selector -> Floki.Finder.find(html_attributes_as_lists, selector)  end,
    "attributes_as_maps" => fn selector -> Floki.Finder.find(html_attributes_as_maps, selector)  end
  },
  time: 10,
  memory_time: 2,
  inputs: %{
    "bench" => "#cite_ref-Pocock1939_1-1"
  }
)

[philss]

Added a suggestion to try, but LGTM!

[philss]

One last thing :)