bpo-44859: Improve error handling in sqlite3 and and raise more accurate exceptions. (GH-27654)

* MemoryError is now raised instead of sqlite3.Warning when
  memory is not enough for encoding a statement to UTF-8
  in Connection.__call__() and Cursor.execute().
* UnicodEncodeError is now raised instead of sqlite3.Warning when
  the statement contains surrogate characters
  in Connection.__call__() and Cursor.execute().
* TypeError is now raised instead of ValueError for non-string
  script argument in Cursor.executescript().
* ValueError is now raised for script containing the null
  character instead of truncating it in Cursor.executescript().
* Correctly handle exceptions raised when getting boolean value
  of the result of the progress handler.
* Add many tests covering different corner cases.

Co-authored-by: Erlend Egeberg Aasland <erlend.aasland@innova.no>

Modules/_sqlite/statement.c

@@ -56,9 +56,6 @@ pysqlite_statement_create(pysqlite_Connection *connection, PyObject *sql)
     Py_ssize_t size;
     const char *sql_cstr = PyUnicode_AsUTF8AndSize(sql, &size);
     if (sql_cstr == NULL) {
-        PyErr_Format(connection->Warning,
-                     "SQL is of wrong type ('%s'). Must be string.",
-                     Py_TYPE(sql)->tp_name);
         return NULL;
     }