Aliases for internal vulnerabilites

### Current Behavior

Aliases in create requests are ignored. the alias shows up in the response but is ignored in gui/db.
Request :
```json
{
"vulnId": "INT-111-111",
"source": "INTERNAL",
"title": "test",
"severity": "MEDIUM",
"cvssV2Vector": null,
"cvssV3Vector": null,
"owaspRRVector": null,
"cwes": [],
"affectedComponents": [],
"aliases" : [{
"cveId": " CVE-2026-21304"
}]
}
```
Response:
```json
{
"vulnId": "INT-111-111",
"source": "INTERNAL",
"title": "test",
"cwes": [],
"severity": "MEDIUM",
"components": [],
"serviceComponents": [],
"uuid": "911a662d-5271-4fbf-b585-c5889aa44cd5",
"aliases": [
{
"cveId": "CVE-2026-21304"
}
],
"affectedProjectCount": 0,
"affectedActiveProjectCount": 0,
"affectedInactiveProjectCount": 0,
"affectedComponents": []
}
```
In update requests the aliases are just ignored
request:
```json
{
"uuid": "911a662d-5271-4fbf-b585-c5889aa44cd5",
"vulnId": "INT-111-111",
"source": "INTERNAL",
"title": "tests",
"severity": "MEDIUM",
"cvssV2Vector": null,
"cvssV3Vector": null,
"owaspRRVector": null,
"cwes": [],
"affectedComponents": [],
"aliases" : [{
"cveId": " CVE-2026-21304"
}]
}
```
Response:
```json
{
"vulnId": "INT-111-111",
"source": "INTERNAL",
"title": "tests",
"cwes": [],
"severity": "MEDIUM",
"components": [],
"uuid": "911a662d-5271-4fbf-b585-c5889aa44cd5",
"aliases": [],
"affectedProjectCount": 0,
"affectedActiveProjectCount": 0,
"affectedInactiveProjectCount": 0
}
```

### Proposed Behavior

Add support for aliases for internal vulnerabilities.

### Checklist

- [x] I have read and understand the [contributing guidelines](https://github.com/DependencyTrack/dependency-track/blob/master/CONTRIBUTING.md#filing-issues)
- [x] I have checked the [existing issues](https://github.com/DependencyTrack/dependency-track/issues) for whether this enhancement was already requested