refactor: replace explicit bit-setting loops with optimized bulk operations

Refactor bitmatrix, colgroup, and layer modules to replace manual iteration with concise `or_where` predicates and bulk inversion calls. This simplifies the codebase and leverages optimized internal implementations for improved performance.

src/obilayeredmap/src/layer.rs

@@ -107,9 +107,7 @@ impl Layer<()> {
         fs::create_dir_all(&presence_dir).map_err(OLMError::Io)?;
         let mut mb = PersistentBitMatrixBuilder::new(n_kmers, &presence_dir).map_err(OLMError::Io)?;
         let mut col = mb.add_col().map_err(OLMError::Io)?;
-        for slot in 0..n_kmers {
-            col.set(slot, true);
-        }
+        col.not();
         col.close().map_err(OLMError::Io)?;
         mb.close().map_err(OLMError::Io)
     }