Remove saturation parameter, delta, and instead use expansionRate as part of the storage request, in preparation for a linear curve of the expanding window definition.
Add a parameter, `saturation` to the network-level configuration, under `SlotReservationConfig`. This parameter represents the percentage of total time before expiry that all addresses are eligible to reserve a slot. Total time is the duration between request creation and expiry. Valid range is [0, 99].
Note, this parameter is not yet used anywhere.
Eric