respect provider strategies on initial adds

[whyrusleeping]

We have provider strategies that define which content gets provided. However, they are only respected on reprovide, for the initial adding of the content, everything currently gets provided regardless of whether or not it should be given the strategy.

We should rework the providers system to address this issue, moving provides out of the add path should also improve the performance of add.

[michaelavila]

This work is being tracked here: #5774 and references this issue, so I'm going to close this issue.