[adkinsrs]

This pull request introduces support for visualizing DominoSignal cell-cell communication analysis outputs within the gEAR portal. It adds user and developer documentation for the new feature, updates references to related portals, and includes new backend and test code to manage DominoSignal datasets and their metadata.

Cell-cell communication feature:

• Added user documentation (docs/analyst/cell_cell.md) describing the cell-cell communication visualization page, including its capabilities (dot plots, river plots/Sankey diagrams, filtering options, and customization).
• Added developer documentation (docs/developer/cell_cell_dev.md) detailing the implementation, file locations, and data handling for the cell-cell communication page, as well as test coverage.

Backend and testing:

• Introduced a new CGI script (www/cgi/get_domino_options.cgi) to list available DominoSignal output files, provide selectable parameter values, and fetch dataset metadata from accompanying JSON files.
• Added a test suite (tests/python/test_dominosignal.py) for the DominoSignal backend, ensuring proper file listing, metadata extraction, and error handling.
• Updated the test documentation to include the new DominoSignal test module.
• Added a .gitignore to keep the DominoSignal cache directory tracked but empty in version control.

Documentation updates:

• Added "NODE from CMTRF" (neuropathy research portal) to the list of gEAR-related portals in README.md, docs/README.md, and docs/developer/README.md. [1] [2] [3] [4]

Minor code update:

• Updated the HiCViewSpec rendering in www/api/resources/gosling_spec.py to pass the prefix argument to the underlying encoding function.