Tree view for loaded rod position data

[a-niem]

This implements a tree view on the loaded rod data, with a focus on their seen status. This tree is updated throughout the working progress and adjusts to the displayed frame/color of rods automatically. This means it expands the corresponding frame and color node while collapsing any previously opened ones. This tree view can also be used to select rods by clicking the respective node. It will also adjust the displayed frame/color of rods automatically. This update also adjusts the process of how rods' seen status is updated during adjustments and how it is propagated through the program. It is now passed through the program using the backend.logger.Action classes.

[dmitrypuzyrev]

There are 2 minor problems with the tree view:

• the particles are not sorted by number (sorting follows the "particle" column in the csv file at the moment)
• the List of rods/Performed actions column in the GUI cannot be made wide enough (see the screenshot with the maximum width for 4K resolution

  )