Support different schema/data DB script users

Allow data and/or schema scripts to be run by different database users.

Fixes gh-5402
Closes gh-5788

spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc

@@ -590,6 +590,8 @@ content into your application; rather pick only the properties that you need.
 	# DATASOURCE ({sc-spring-boot-autoconfigure}/jdbc/DataSourceAutoConfiguration.{sc-ext}[DataSourceAutoConfiguration] & {sc-spring-boot-autoconfigure}/jdbc/DataSourceProperties.{sc-ext}[DataSourceProperties])
 	spring.datasource.continue-on-error=false # Do not stop if an error occurs while initializing the database.
 	spring.datasource.data= # Data (DML) script resource reference.
+	spring.datasource.data-username= # User of the database to execute DML scripts (if different).
+	spring.datasource.data-password= # Password of the database to execute DML scripts (if different).
 	spring.datasource.dbcp.*= # Commons DBCP specific settings
 	spring.datasource.dbcp2.*= # Commons DBCP2 specific settings
 	spring.datasource.driver-class-name= # Fully qualified name of the JDBC driver. Auto-detected based on the URL by default.
@@ -601,6 +603,8 @@ content into your application; rather pick only the properties that you need.
 	spring.datasource.password= # Login password of the database.
 	spring.datasource.platform=all # Platform to use in the schema resource (schema-${platform}.sql).
 	spring.datasource.schema= # Schema (DDL) script resource reference.
+	spring.datasource.schema-username= # User of the database to execute DDL scripts (if different).
+	spring.datasource.schema-password= # Password of the database to execute DDL scripts (if different).
 	spring.datasource.separator=; # Statement separator in SQL initialization scripts.
 	spring.datasource.sql-script-encoding= # SQL scripts encoding.
 	spring.datasource.tomcat.*= # Tomcat datasource specific settings