### Elasticsearch Version

7.x, 8.x

### Installed Plugins

_No response_

### Java Version

_bundled_

### OS Version

Darwin 

### Problem Description

A data stream must have an index template that matches it in order to exist.
When managing index templates we want to make sure we don't leave a
data stream without a [corresponding index template](https://github.com/elastic/elasticsearch/blob/acf9968f9d397d755d5ad9fcf815cca23bbeda61/server/src/main/java/org/elasticsearch/cluster/metadata/MetadataIndexTemplateService.java#L918).

The `dataStreamsUsingTemplate` check uses the index pattern of the index 
templates to conclude if a template is used by a data stream, however it should
be enhanced to check the priority too as there can only be only one index template
that matches a data stream and it's the one with the highest priority.

### Steps to Reproduce

Create an ILM policy
```
PUT _ilm/policy/testing_yo
{
  "policy": {
    "phases": {
      "warm": {
	"actions": {
	  "shrink": {
          "number_of_shards": 1
	  }
        }
      }
    } 
  }
}
```

Create an index template with the `data_stream` option:
```
PUT _index_template/logs_data_stream
{
	"index_patterns": [ "logs*", "te*", "bar*" ],
	"data_stream": {},
        "priority": 100,
	"template" : {
	  "settings": {
            "index.number_of_shards": 3,
	    "index.lifecycle.name": "testing"
	  }
	}
}
```

Create the data stream
```
POST logs_test/_doc 
{
  "message": "testing",
  "@timestamp": "1591890611"
}
```

Create a new index template that would match this data stream with a higher priority
```
PUT _index_template/higher_logs_data_stream
{
	"index_patterns": [ "logs*", "te*", "bar*" ],
	"data_stream": {},
        "priority": 500,
	"template" : {
	  "settings": {
            "index.number_of_shards": 3,
	    "index.lifecycle.name": "testing"
	  }
	}
}
```

Attempt to delete the previous, lower priority index template:
```
DELETE _index_template/logs_data_stream
```

### Logs (if relevant)

_No response_
server/src/test/java/org/elasticsearch/cluster/metadata/MetadataIndexTemplateServiceTests.java
state = service.addIndexTemplateV2(state, true, "my-template", it);
        List<Map<String, AliasMetadata>> resolvedAliases = MetadataIndexTemplateService.resolveAliases(state.metadata(), "my-template");
        
        assertThat(resolvedAliases, equalTo(List.of(a3, a1, a2)));
    }
    public void testAddInvalidTemplate() throws Exception {
        ComposableIndexTemplate template = new ComposableIndexTemplate(
            Collections.singletonList("a"),
            null,
            Arrays.asList("good", "bad"),
            null,
            null,
            null
        );
        ComponentTemplate ct = new ComponentTemplate(new Template(Settings.EMPTY, null, null), null, null);
        final MetadataIndexTemplateService service = getMetadataIndexTemplateService();
        CountDownLatch ctLatch = new CountDownLatch(1);
        service.putComponentTemplate(
            "api",
            randomBoolean(),
            "good",
            TimeValue.timeValueSeconds(5),
            ct,
            ActionListener.wrap(r -> ctLatch.countDown(), e -> {
                logger.error("unexpected error", e);
                fail("unexpected error");
            })
        );
        ctLatch.await(5, TimeUnit.SECONDS);
        InvalidIndexTemplateException e = expectThrows(InvalidIndexTemplateException.class, () -> {