Improve rotation to ZRT

Now we use IRIS metadata (dip and azimuth for each component) to rotate all stations to ZNE, even if they were already ostensibly at ZNE, prior to rotating from NE to RT. This addresses issues where the actual orientation is surprisingly off — e.g., a supposed "north" component having an azimuth of 10°. Previously we just issued a warning for these problem stations.

The code prints a message for each channel it modifies during the rotation to ZNE step. This message includes true dip and azimuth information from IRIS.

I also updated some testing stuff. I had to update the test data now that the input data for the inversion are slightly different (better!).