chore(gfql): shrink cypher call procedures

[lmeyerov]

Summary

• DRYs local Cypher CALL procedure value-column derivation by reusing source-column lookup and shared multi-column out_col diagnostics.
• DRYs computed-output column rename-map construction shared by node/edge backend results.
• Centralizes NetworkX backend dependency/parameter error plumbing while keeping intent-named node/edge/graph handlers and preserving the no-SciPy graphistry.nx.pagerank path.

Refs #1058.

Reporting

• Production: +107 / -207, net -100 LOC (graphistry/compute/gfql/cypher/call_procedures.py)
• Tests / fixtures / baselines: +0 / -0, net 0 LOC
• Comments / docs / changelog: +1 / -0, net +1 LOC (CHANGELOG.md)
• Compiler-plan surface touched: no. This stays inside CALL procedure helper implementation; route names, logical/physical plan semantics, dispatch contracts, structured errors, source spans, and validation seams are preserved.

Audit Notes

• No Arrow / validate='autofix' path exists in call_procedures.py; no deletion there.
• call/validation.py remains the owner for igraph/cuGraph option validation; this PR does not edit adjacent validation territory.
• No defer-code branch exists in the target file.
• graphistry.nx.pagerank still uses the local no-SciPy pagerank path because core CI intentionally does not install SciPy; the shrink is in shared NetworkX dispatcher/error plumbing, not dependency expansion.

Validation

• python3 -m pytest -q graphistry/tests/compute/gfql/cypher/test_lowering.py -k 'call and not real_cugraph' -> 49 passed, 12 skipped, 1020 deselected
• python3 -m pytest -q graphistry/tests/compute/gfql/cypher/test_lowering.py -k call -> 49 passed, 18 skipped, 1014 deselected
• ./bin/ruff.sh graphistry/compute/gfql/cypher/call_procedures.py -> passed
• ./bin/typecheck.sh graphistry/compute/gfql/cypher/call_procedures.py -> passed
• python3 -m pytest -q graphistry/tests/test_schema_artifacts.py graphistry/tests/test_viz_settings.py -> 11 passed
• python3 -m graphistry.devschemas.export --check -> passed, no schema drift
• git diff --check -> passed
• DGX RAPIDS 26.02: RAPIDS_VERSION=26.02 PROFILE=gfql WITH_IMAGE_BUILD=1 TEST_FILES="graphistry/tests/compute/gfql/cypher/test_lowering.py -k call" docker/test-rapids-official-local.sh -> 62 passed, 5 skipped, 1014 deselected
• DGX RAPIDS 25.02: RAPIDS_VERSION=25.02 PROFILE=gfql WITH_IMAGE_BUILD=1 TEST_FILES="graphistry/tests/compute/gfql/cypher/test_lowering.py -k call" docker/test-rapids-official-local.sh -> 62 passed, 5 skipped, 1014 deselected
• Review skill: converged after 4 waves total, including 2 post-CI-fix waves; no findings
• Full PR CI: green, including core-python 3.8-3.14, GFQL core, TCK-GFQL, schema artifacts, changed-line-coverage, docs/RTD, pandas compatibility, graphviz, polars, DGL, Neo4j, and frontend gates