Deprecated storage.content-get-range (cassandra storage unsupported) got dropped in the storage
in favor of a more compliant api storage.content-get-partition  (cassandra storage supported)
The text indexers were the sole users of that deprecated api.
This migrates them to move to the same pattern of using a partition.
This simplifies the setup as no range is to be computed (the api does it \o/).
The production impact is to stop current indexers, disable all their current tasks from the scheduler and change their input in the scheduler db.
Note that it's wip as it remains tests using the old interface to fix.
Also, this fixes:
- mistyped codes following the migration to storage 0.12.0. This cannot be untangled from the partition migration though.
- build 
Related to T645