NI-FGEN API has no repeated capability for Data Markers

[ni-jfitzger]

Description of issue

Marker Events and Data Marker Events have different repeated capabilities that they are accessible through.

Markers are accessible through 'MarkerN' (where N is a decimal) repeated capabilities.
Data Markers are accessible through 'DataMarkerN' repeated capabilities.

The Python API currently provides no DataMarker repeated capability, so the only way to access data marker attributes is with the channels repeated capability.

This happened because markers and data markers were conflated in the metadata. 'markers' is listed as the repeated capability type for data marker event attributes.

System report

ni-fgen package release: 1.4.1.
System info isn't really relevant (in my opinion).

Steps to reproduce issue

Example 1 (errors)

with nifgen.Session("Dev1", options= {'simulate': True, 'driver_setup': {'Model': '5441', 'BoardType': 'PXI'}}) as session:
    session.markers[0].data_marker_event_data_bit_number=0

Example 2 (errors)

with nifgen.Session("Dev1", options= {'simulate': True, 'driver_setup': {'Model': '5441', 'BoardType': 'PXI'}}) as session:
    session.data_markers[0].data_marker_event_data_bit_number=0

Example 3 (errors)

with nifgen.Session("Dev1", options= {'simulate': True, 'driver_setup': {'Model': '5441', 'BoardType': 'PXI'}}) as session:
    session.data_marker_event_data_bit_number=0

Example 4 (no error)

with nifgen.Session("Dev1", options= {'simulate': True, 'driver_setup': {'Model': '5441', 'BoardType': 'PXI'}}) as session:
    session.channels['DataMarker0'].data_marker_event_data_bit_number=0