Collection prefix support for MongoDB job repository

[SHINMH]

📝 Description
This PR adds collection prefix support for MongoDB job repository, mirroring the existing tablePrefix functionality in JDBC job repository. This enables multi-application support, environment isolation, and easier management of MongoDB collections in Spring Batch deployments.

🎯 Motivation
Currently, MongoDB job repository uses hardcoded collection names (BATCH_JOB_INSTANCE, BATCH_JOB_EXECUTION, etc.), making it difficult to:

Run multiple Spring Batch applications against the same MongoDB database
Isolate different environments (dev, test, prod)
Manage collections with custom naming conventions

🔧 Changes
EnableMongoJobRepository: Add collectionPrefix parameter (defaults to "BATCH_")
MongoJobRepositoryFactoryBean: Add collection prefix support
MongoDB DAO classes: Support configurable collection names via constructor parameters
BatchRegistrar: Pass collection prefix from annotation to factory bean
Tests: Add integration tests for collection prefix functionality

💡 Usage Example

@EnableBatchProcessing
@EnableMongoJobRepository(collectionPrefix = "MY_APP_")
public class BatchConfiguration {
    // Configuration
}

This will create collections like:
MY_APP_JOB_INSTANCE
MY_APP_JOB_EXECUTION
MY_APP_STEP_EXECUTION

Closes: collectionPrefix for MongoDB Job repository #4980