Get the list of providers on an alternative way and improved regexes for getting the url

See https://github.com/simplesconsultoria/sc.embedder/blob/262d279b25878d11706eb25c9b94a699789ed4e5/src/sc/embedder/utility.py#L7

The way it's implemented right now for example gives the following error for https links in some providers:

```
2020-01-13 16:44:19 INFO sc.embedder There are no endpoints available for https://vimeo.com/384531827
```

Don't know if it's possible, but I would suggest taking https://github.com/itteco/iframely/blob/master/lib/plugins/system/oembed/providers.json inside the package and creating a dictionary that has these validations at runtime: upgrading the providers would mean just downlading a new json and adding it to the package. Using this approach we fix the regex problem as well since they are improved.

Start with src/sc/embedder/utility.py around the provider-list and URL-validation logic, then inspect iframely's providers.json. Check how the current logic handles the Vimeo HTTPS example and determine how the packaged provider data would be loaded at runtime. Done means the provider list can be updated through the JSON file and HTTPS provider URLs are recognized correctly.

Written by the indexing model from the issue text.