Allow double-quoted string literals in PRAGMA.

Allow double quoted string literals as pragma values but do not
treat them as an identifier because it is impossible from the
surrounding context to determine whether it is a column, table,
or database identifier.

Author: nwronski

src/grammar.pegjs

@@ -1100,9 +1100,17 @@ pragma_value
   / pragma_value_literal
   / pragma_value_name
 
+/**
+ * @note
+ *   Allow double quoted string literals as pragma values but do not treat
+ *   them as an identifier because it is impossible from the surrounding
+ *   context to determine whether it is a column, table, or database
+ *   identifier.
+ */
 pragma_value_literal
   = literal_number_signed
   / literal_string
+  / literal_text
 
 /**
  * @note