### 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/main/java/org/elasticsearch/cluster/metadata/MetadataIndexTemplateService.java
final Predicate<String> predicate;
        if (templateNameOrWildcard.length > 1) {
            predicate = name -> Arrays.asList(templateNameOrWildcard).contains(name);
        } else {
            predicate = name -> Regex.simpleMatch(templateNameOrWildcard[0], name);
        }
        final Set<String> matchingComponentTemplates = metadata.componentTemplates()
            .keySet()
            .stream()
            .filter(predicate)
            .collect(Collectors.toSet());
        final Set<String> componentsBeingUsed = new HashSet<>();
        final List<String> templatesStillUsing = metadata.templatesV2().entrySet().stream().filter(e -> {
            Set<String> intersecting = Sets.intersection(new HashSet<>(e.getValue().composedOf()), matchingComponentTemplates);
            if (intersecting.size() > 0) {
                componentsBeingUsed.addAll(intersecting);
                return true;
            }
            return false;
        }).map(Map.Entry::getKey).collect(Collectors.toList());
        if (templatesStillUsing.size() > 0) {
            throw new IllegalArgumentException(
                "component templates "
                    + componentsBeingUsed
                    + " cannot be removed as they are still in use by index templates "
                    + templatesStillUsing
            );
        }
    }
    /**