Change CRSMatrixDescriptor constructors

- change parametrs to ease template deduction
- add a square matrix constructor (ie: number of columns is deduced
from the number of rows)

src/algebra/CRSMatrixDescriptor.hpp

@@ -248,9 +248,9 @@ class CRSMatrixDescriptor
     }
   }
 
-  CRSMatrixDescriptor(const IndexType nb_rows, const IndexType nb_columns, const Array<IndexType>& non_zeros)
-    : m_nb_rows{nb_rows},
-      m_nb_columns{nb_columns},
+  CRSMatrixDescriptor(const size_t nb_rows, const size_t nb_columns, const Array<IndexType>& non_zeros)
+    : m_nb_rows(nb_rows),
+      m_nb_columns(nb_columns),
       m_row_map{this->_computeRowMap(non_zeros)},
       m_values(m_row_map[m_row_map.size() - 1]),
       m_column_indices(m_row_map[m_row_map.size() - 1]),
@@ -268,6 +268,10 @@ class CRSMatrixDescriptor
     }
   }
 
+  CRSMatrixDescriptor(const size_t nb_rows, const Array<IndexType>& non_zeros)
+    : CRSMatrixDescriptor(nb_rows, nb_rows, non_zeros)
+  {}
+
   ~CRSMatrixDescriptor() = default;
 };