Extract multiple doc numbers from a single cell

Previously, if a cell contained links to multiple documents, only the number of the first one was retrieved. It is now possible to extract all the available document numbers from a cell because the method now loops on all the contained anchors.
Get labels when parsing document links

This also does refactoring in order to get the document format with the same regular expression as the other pieces of information.
[fix] Regular expression was skipping some links
[refactor] Improve performance to get doc numbers

The document numbers are now extracted from already parsed data instead of parsing each link twice. We thus remove useless DOM filtering and regular expression executions.