Feature: Pass user info over when syncing content and media

[KevinJump]

Adds user info to the user and media configs, so we can have a go at preserving user info in syncs.

• user info will be reliant on the users existing on the target site, so if users are not synced this will fail back to -1 (admin user).
• will remain off by default adding "IncludeUserInfo" setting to handlers will turn it on.