Simultaneous horizontal/vertical steps in BBA measurement

[kparasch]

Title

Extend BBA measurement to support simultaneous H/V scans

Summary

This PR adds an HV BBA measurement mode that scans horizontal and vertical correctors together and stores the result in a dedicated HV_data object. The mode emits new BBA status codes, supports live IOS updates, can be analyzed into separate horizontal and vertical BBAAnalysis results, and is saved through the public measure_bba() wrapper.

Changes

• Added BBACode.HORIZONTAL_VERTICAL, HORIZONTAL_VERTICAL_DONE, and HORIZONTAL_VERTICAL_IOS_READY.
• Added HV_data to BBA_Measurement.
• Extended one_plane_loop() to handle plane="HV" by stepping both correctors at each scan point.
• Added HDF5-safe serialization for HV tuple fields:
  • corrector stored as a byte-string array
  • dk0l and initial_k0l stored as numeric arrays
  • magnet_type stored as its string value
• Added measure_bba(..., plane="HV") save handling.
• Fixed measure_bba(..., skip_cycle=True) so it is passed through to BBA_Measurement.generate().
• Made BBAAnalysis.analyze(HV_data) return separate H/V analysis results.