(ITS#8880) back-sql: Support deferencing aliases

[hibethy73]

Full_Name: Younghee Bae
Version: 2.4.45
OS: Linux
URL: ftp://ftp.openldap.org/incoming/Younghee-Bae-180718.patch
Submission from: (NULL) (222.112.181.231)


I added alias handling for back-sql.