fix: only get packageId from database (#768)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

- **Refactor**
- Enhanced the internal process for retrieving package version details,
resulting in more accurate and reliable version information.
- Streamlined the handling of missing package data to reduce unexpected
issues.
- Optimized overall data processing, contributing to improved stability
and a smoother user experience.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Author: fengmk2

app/core/service/PackageVersionService.ts

@@ -125,10 +125,10 @@ export class PackageVersionService {
 
   async findBlockInfo(fullname: string) {
     const [ scope, name ] = getScopeAndName(fullname);
-    const pkg = await this.packageRepository.findPackage(scope, name);
-    if (!pkg) {
+    const packageId = await this.packageRepository.findPackageId(scope, name);
+    if (!packageId) {
       return null;
     }
-    return await this.packageVersionBlockRepository.findPackageBlock(pkg.packageId);
+    return await this.packageVersionBlockRepository.findPackageBlock(packageId);
   }
 }