Unify namespace strucuture

src/SparseTransform.Tests/Library/ColorerTests.cs

...sform.Tests/Library/DataStructures/AdjacencyGraphTests.cs

...sform.Tests/Library/DataStructures/BipartiteGraphTests.cs

...ansform.Tests/Library/DataStructures/DoubleMatrixTests.cs

...eTransform.Tests/Library/DataStructures/GraphNodeTests.cs

...nsform.Tests/Library/DataStructures/IntegerMatrixTests.cs

...arseTransform.Tests/Library/DataStructures/MatrixTests.cs

src/SparseTransform/Colorer.cs

src/SparseTransform/ConversionManager.cs

src/SparseTransform/Convert/ColoredDotWriter.cs

src/SparseTransform/Convert/DotWriter.cs

src/SparseTransform/Convert/IReader.cs

src/SparseTransform/Convert/IWriter.cs

src/SparseTransform/Convert/MatrixMarketReader.cs

src/SparseTransform/Convert/MatrixMarketWriter.cs

src/SparseTransform/DataStructures/AdjacencyGraph.cs

src/SparseTransform/DataStructures/BipartiteGraph.cs

src/SparseTransform/DataStructures/DoubleMatrix.cs

src/SparseTransform/DataStructures/GraphNode.cs

src/SparseTransform/DataStructures/IGraph.cs