Added a new selection GUI and a Result viewer

[klemengit]

This PR is related to #51 .

It implements two features:
Upgraded selection interface

• Implemented in SelectionGUI class
• Uses pyqtgraph to display image and points without lag
• Uses pyqt6 (optional dependency)
• Has two modes:
  • Selection mode: select points using a polygon, along the line, single point, brush
  • Filter mode: filter the selected points based on some criterion. Currently implemented: Shi-Tomasi and gradient direction. Here, further algorithms are planned (@ThijsIllimited )

Result viewer

• Implemented in ResultViewer class
• Uses pyqtgraph to display image and points without lag
• Uses pyqt6 (optional dependency)
• Plan is to add export functionality and display of mode shapes (automatic animation of complex shapes)

[jankoslavic]

Great effort @klemengit

[klemengit]

Now added:
SelectionGUI:

• Updated filtering interface
• Updated brush selection
• Added point retrieval methods: get_selected_points (all points from selection mode) and get_filtered_points (points that were filtered).
• Calling Points.points (where Points is instance of SelectionGUI) returns the filtered points, but if they do not exist (no filtering was done), all selected points are returned.

ResultViewer:

• Mode shape visualization
• Export to MP4 (with frame range and region selection)

@jankoslavic if you agree, I think we can merge this PR 🙂

[jankoslavic]

DEar @klemengit ; this is a great PR. I will now merge it!