Add support for Bean Overriding in transactionoutbox-spring

[ironhide0396]

[Copied over from #681]

It is quite a normal use case for developers to have a baseBean in the production files and have an overridden one in the test files. The bean in the test file is marked with @Primary so that it takes precedence when being invoked from tests.

Now, in case of using transactionoutbox-spring, the following method

@Override
public String getName(Class<?> clazz) {
    String[] beanNames = applicationContext.getBeanNamesForType(clazz);
    if (beanNames.length > 1) {
      throw new IllegalArgumentException(
          "Type "
              + clazz.getName()
              + " exists under multiple names in the context: "
              + Arrays.toString(beanNames)
              + ". Use a unique type.");
    }
    if (beanNames.length == 0) {
      throw new IllegalArgumentException(
          "Type " + clazz.getName() + " not available in the context");
    }
    return beanNames[0];
}

throws errors when there are more than 2 beans for the same class.

Action Items :

1. Modify above mentioned class to return the bean definition for a class which has a higher precedence (marked using @Primary)
2. Add tests for above corner case.