added blob interface to backend binder classes

backends/postgres/src/postgres_dialect.cpp

@@ -2,13 +2,17 @@
 
 #include "matador/sql/dialect_builder.hpp"
 
-[[maybe_unused]] const matador::sql::dialect* get_dialect() {
+[[maybe_unused]] const matador::sql::dialect *get_dialect()
+{
   using namespace matador::sql;
   const static dialect d = dialect_builder::builder()
     .create()
     .with_placeholder_func([](size_t index) {
       return "$" + std::to_string(index);
     })
+    .with_data_type_replace_map({
+                                  {data_type_t::type_blob, "BYTEA"}
+                                })
     .with_default_schema_name("public")
     .build();
   return &d;