[System]: Request for Logs and Metrics wide component template

### Integration Name

System [system]

### Dataset Name

system.core

### Integration Version

2.13.0

### Agent Version

9.3.0

### OS Version and Architecture

Redhat

### User Goal

I would like to see a component template for example `logs-system@custom` and `metrics-system@custom` added to the underlying system index templates. Currently there is a system@custom component template which is used by both `metrics-system.*` and `logs-system.*`. We are looking at for example set a ILM policy on for `system-metrics.*`which would also set downsample etc. While logs-system.* would see other retentions and it would also not be necessary to set downsample for logs.

So for example adding metrics-system@custom as seen below to the index templates.
```
"composed_of": [
"metrics@tsdb-settings",
"metrics-system.core@package",
"metrics@custom",
"system@custom",
"metrics-system@custom", // New feature proposed
"metrics-system.core@custom",
"ecs@mappings",
".fleet_globals-1",
".fleet_agent_id_verification-1"
],
```

Adding this would add an intermediate step between all system and the full dataset splitted between logs and metrics. For metrics there is 13 component templates to modify to modify the ILM Policies, which is doable but tedious. :)

### Existing Features

```
PUT _index_template/metrics-system.core
{
"priority": 200,
"template": {
"mappings": {
"_meta": {
"package": {
"name": "system"
},
"managed_by": "fleet",
"managed": true
}
},
"settings": {
"index": {
"mode": "time_series"
}
}
},
"index_patterns": [
"metrics-system.core-*"
],
"data_stream": {
"hidden": false,
"allow_custom_routing": false
},
"composed_of": [
"metrics@tsdb-settings",
"metrics-system.core@package",
"metrics@custom",
"system@custom",
"metrics-system.core@custom",
"ecs@mappings",
".fleet_globals-1",
".fleet_agent_id_verification-1"
],
"ignore_missing_component_templates": [
"metrics@custom",
"system@custom",
"metrics-system.core@custom"
],
"_meta": {
"package": {
"name": "system"
},
"managed_by": "fleet",
"managed": true
}
}
```

### What did you see?

N/A

### Anything else?

_No response_