Tenant's watch is loading in memory ALL data from tenants

[RafaPolit]

Describe the bug
The tenants watcher is loading the entire Tenants DB into memory when a single property changes in any of the tenants.

This is causing severe overhead when updating things that are not relevant to Uwazi. There needs to be an overhaul of the process, but in the meantime it's good enough to limit the properties to the ones defined in schema.