Fix allocation chart sort by name feature

[talyssonoc]

Looks like sorting by name in the allocation chart table is not working properly. All the other ones are fine.

[bedreski]

So, after trying to analize the aspects of the problem, it could be:

1. The time hidden column used to sort "allocated until" column
2. The different values of "allocated until" rows (date type for allocated users and string for "Not allocated" status)
3. Some configuration of DataTable that would not working properly

For now, I received instructions to leave this issue, due to Admin pages being refactored.