Simplified multi-file GWF read for TimeSeries and friends
This PR simplifies the TimeSeries
I/O for GWF by removing the custom multiprocessing from timeseries.io.cache
, replacing it with calls to io.mp.read_multi
similar to the EventTable
.
This removes some possible optimisations that can be used when reading multiple files in a single process, but it makes the code much easier to maintain.