Plotly visualizer

[OutlyingWest]

• The visualizer was refactored into a backend-based architecture: shared orchestration logic was moved to the base PerformanceVisualizer, and rendering was split into MatplotlibPerformanceVisualizer and
  PlotlyPerformanceVisualizer.
• Backend selection was added via a magic command argument; if not explicitly provided, the default backend is taken from settings.
• Tests were added in tests/test_magic_commands.py for backend switching and fallback to the settings-defined backend.
• A dependency for Plotly export (kaleido) was added

[github-actions]

Docs preview: https://ScaDS.github.io/jumper_ipython_extension/pr-34/