loopdb: provide function NewSqlWriteOpts

It returns transaction options resulting in full (read+write) tx.

Use it in loopdb and instantout stores.

loopdb/sqlite.go

@@ -323,7 +323,7 @@ type SqliteTxOptions struct {
 	readOnly bool
 }
 
-// NewSqlReadOpts returns a new KeyStoreTxOptions instance triggers a read
+// NewSqlReadOpts returns a new KeyStoreTxOptions instance that triggers a read
 // transaction.
 func NewSqlReadOpts() *SqliteTxOptions {
 	return &SqliteTxOptions{
@@ -331,6 +331,14 @@ func NewSqlReadOpts() *SqliteTxOptions {
 	}
 }
 
+// NewSqlWriteOpts returns a new KeyStoreTxOptions instance that triggers a
+// write (regular) transaction.
+func NewSqlWriteOpts() *SqliteTxOptions {
+	return &SqliteTxOptions{
+		readOnly: false,
+	}
+}
+
 // ReadOnly returns true if the transaction should be read only.
 //
 // NOTE: This implements the TxOptions interface.