Updating bean - L2 Bean cache update + l2 cache update on "Many Ids" when they have not change - can lead to race

[rbygrave]

Steps to reproduce

	@Test
	public void testLazyLoad(){

		DB.script().run("/test-setup.sql");
		// Please execute the script in [test.sql] every time you execute the test to reset the data
		Config c1 = new QConfig().setUseCache(true).setId("config_1").findOne();
		List<ConfCp> confCpList = c1.getConfCpList();
		if(confCpList != null && !confCpList.isEmpty()){
			List<ConfCpCon> conList = confCpList.get(0).getConList();
			if (!conList.isEmpty()) {
				conList.get(0);
			}
		}
		c1.setConfigName("c1");

		Config c2 = new QConfig().setUseCache(true).setId("config_1").findOne();
		ConfCp confCp = c2.getConfCpList().get(0);

		ConfCpCon con = new ConfCpCon();
		con.setId("newCon");
		con.setEnabled("N");
		confCp.getConList().clear();
		confCp.getConList().add(con);

		c2.getConfCpList().clear();
		c2.getConfCpList().add(confCp);

		//DB.markAsDirty(c2);
		c2.save();

		c1.save();   // THIS UPDATE HERE ... will also push L2 cache update of ManyIds which have changed by c2.save()

		Config config = new QConfig().setUseCache(true).setId("config_1").findOne();
		List<ConfCp> confCpList1 = config.getConfCpList();
		if(confCpList1 != null && !confCpList1.isEmpty()){
			List<ConfCpCon> conList = confCpList1.get(0).getConList();
			if (conList != null) {
				for (ConfCpCon confCpCon : conList) {
					System.out.println("---- id: "+confCpCon.getId());
					// An exception will be thrown here
					// EntityNotFoundException: Bean not found during lazy load or refresh
					System.out.println(confCpCon.getId()+":"+confCpCon.getEnabled());
				}
			}
		}

	}

The issue can be seen in the logs as the last 2 PUT calls here should not really be made as the collection hasn't actually been mutated in terms of additions or removals.

14:01:51.160 [main] DEBUG io.ebean.SUM - txn[1006] Updated [Config] [config_1]
14:01:51.161 [main] DEBUG io.ebean.TXN - txn[1006] Commit
14:01:51.161 [main] DEBUG io.ebean.cache.BEAN -    UPDATE Config(config_1)  changes:{configName=c1, version=2}
14:01:51.161 [main] DEBUG io.ebean.cache.COLL -    PUT Config(config_1).confCpList - ids:[cp_id]
14:01:51.162 [main] DEBUG io.ebean.cache.COLL -    PUT ConfCp(cp_id).conList - ids:[confCpCon]