Action labels do not match actual action

[RexxarCHL]

It seemed like there are inconsistencies between the action label string and the actual action performed by the robot.

Items to check include:

1. Make sure the goal strings match for every .h5f file
2. Show the string label for each goal timestamp to make sure the actions match the label

Utilize view_convert_dataset to check these two items.

[RexxarCHL]

Modified view_convert_dataset to check label consistency. See #531
Initial results on a small subset of files, 10 files blocks only and 15 files with plush, suggest that:

1. No inconsistency between action label sequence
2. The actual action performed by the robot match action label.

[RexxarCHL]

Randomly checked the first 2000 files in blocks_only subset.
All action labels are consistent. Robot actions match action labels.