Make BatchDataSourceScriptDatabaseInitializer be aware of customized maxVarCharLength

[quaff]

Spring Boot could auto-scale length of long string columns by replacing VARCHAR(2500)/VARCHAR2(2500 to VARCHAR($maxVarCharLength)/VARCHAR2($maxVarCharLength in sql before executing it.

It rely on GH-44799 to allow user to customize the length.

[quaff]

@fmbenhassine WDYT?

[wilkinsona]

We've considered features in the past that would require us to pre-process a bundled SQL script to modify it and rejected them due to the complexity and how brittle it would be. The same reasoning applies here. If there's sufficient demand for this, it should be implemented as a first-class feature in Spring Batch with it providing templated schema files specifically for this sort of configuration.