Add more examples

[duembgen]

This pull request includes updates to the popcor repository, focusing on improving functionality and code organization for lifter classes and associated utilities. The most significant changes involve refactoring constants and methods in the RangeOnlyLifter class, enhancing sampling methods, and improving plotting functionality across multiple files. Additionally, documentation and references have been updated for consistency.

Updates to lifter classes:

• popcor/base_lifters/range_only_lifter.py: Refactored constants such as NOISE, SCALE, and MIN_DIST into the RangeOnlyLifter class for better encapsulation. Added new sampling methods (sample_landmarks_filling_space) and improved sample_theta to avoid numerical issues with landmarks. Introduced warnings for invalid samples after a set number of trials. [1] [2] [3]

• popcor/base_lifters/state_lifter.py: Added the get_valid_samples method to generate valid samples while ensuring they do not violate constraints. Improved the local_solver method to handle ignored arguments and added warnings for unsupported method overrides. [1] [2]

• popcor/examples/rotation_lifter.py: Enhanced the plot method to visualize ground truth and estimates using frames. Updated sample_theta to return matrices instead of flattened arrays for better usability. [1] [2]

Enhancements to plotting utilities:

• popcor/utils/plotting_tools.py: Updated the plot_frame function to handle both 2D and 3D rotation matrices (theta) and added support for custom plot markers and line styles. Improved the function's flexibility for visualization purposes. [1] [2]

Documentation and reference updates:

• CONTRIBUTING.md: Fixed broken links by updating paths to reflect the new repository structure (popcor instead of popr). [1] [2]
• README.md: Removed redundant documentation deploy badge.

(created by Copilot, checked by FD)