…xum HTTP tracker

with only one infohash in the URL:

http://localhost:7070/scrape?info_hash=%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0

It does not allow more than one infohas yet.

THat dependency will be use to store URL query param in a MultiMap
struct, becuase query params can have multiple values like this:

```
param1=value1&param1=value2
```

The multimaps allows to add multiple values to a HashMap.

… same param

The `torrust_tracker::http::axum_implementation::query` allow mutiple
values for the same URL query param, for example:

```
param1=value1&param2=value2
```

It's needed in the `scrape` request:

http://localhost:7070/scrape?info_hash=%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0&info_hash=%3B%24U%04%CF%5F%11%BB%DB%E1%20%1C%EAjk%F4Z%EE%1B%C0

This function returns the data we need for a scrape response regardless
the method that the client is using to communicate with the tracker (UDP or
HTTP).

…acker