YT-CPPHGL-9: Introduce storage layout tags to define the layout of incidence list and matrix representation models

[SpectraL519]

• Defined new vertex_major_t and hyperedge_major_t implementation layout tags with utility methods for retrieving the major and minor elements
• Replaced the current implementation tags with template list_t and matrix_t tags parametrized with a storage layout tag
• Merged the undirected_hyperedge_list and undirected_vertex_list classes into a single template class undirected_incidence_list<LayoutTag>
• Add a LayoutTag template parameter to the unidrected_incidence_matrix class and aligned its implementation to use layout-dependent behaviour
• Aligned the hypergraph_traits type and related utility to use the new tags

[Copilot]

Pull request overview

This PR introduces storage layout tags (vertex_major_t and hyperedge_major_t) to parameterize hypergraph implementation models, enabling unified handling of different storage layouts for incidence lists and matrices.

Key Changes:

• Introduced layout tag infrastructure with vertex_major_t and hyperedge_major_t providing utility methods for layout-aware element access
• Unified undirected_hyperedge_list and undirected_vertex_list into a single template undirected_incidence_list<LayoutTag>
• Updated undirected_incidence_matrix with layout tag parameterization for flexible row/column orientation

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 19 comments.

Show a summary per file

File	Description
include/hgl/impl/layout_tags.hpp	Defines new vertex_major_t and hyperedge_major_t layout tags with utility methods
include/hgl/impl/impl_tags.hpp	Updates implementation tags to template-based list_t and matrix_t parameterized by layout tags
include/hgl/impl/incidence_list.hpp	New unified incidence list implementation replacing separate vertex and hyperedge list classes
include/hgl/impl/incidence_matrix.hpp	Updated incidence matrix with layout tag template parameter and layout-dependent operations
include/hgl/hypergraph_traits.hpp	Updated traits aliases to use new parameterized implementation tags
tests/source/hgl/test_incidence_list.cpp	New test file for unified incidence list implementation covering both layout variants
tests/source/hgl/test_incidence_matrix.cpp	Extended tests to cover both vertex-major and hyperedge-major matrix layouts
tests/source/hgl/test_hypergraph.cpp	Updated test instantiations to include all layout and implementation combinations
tests/source/hgl/test_vertex_list.cpp	Removed (functionality merged into test_incidence_list.cpp)
tests/source/hgl/test_hyperedge_list.cpp	Removed (functionality merged into test_incidence_list.cpp)
include/hgl/impl/vertex_list.hpp	Removed (replaced by incidence_list.hpp)
include/hgl/impl/hyperedge_list.hpp	Removed (replaced by incidence_list.hpp)

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[Copilot]

Spelling error: "incicence" should be "incidence"

[SpectraL519]

ok