Move package settings to package instead of being tied to version (#37026)

Unties settings page from package version and adds button to delete the
package version
Settings page now allows for deletion of entire package and it's
versions as opposed to a single version

Adds an API endpoint to delete the entire package with all versions from
registry

fixes: https://github.com/go-gitea/gitea/issues/36904

Co-Authored-By: gemini-3-flash

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Giteabot <teabot@gitea.io>

models/packages/package_version.go

@@ -157,6 +157,12 @@ func DeleteVersionByID(ctx context.Context, versionID int64) error {
 	return err
 }
 
+// DeleteVersionsByPackageID deletes all versions of a specific package
+func DeleteVersionsByPackageID(ctx context.Context, packageID int64) error {
+	_, err := db.GetEngine(ctx).Where(builder.Eq{"package_id": packageID}).Delete(&PackageVersion{})
+	return err
+}
+
 // HasVersionFileReferences checks if there are associated files
 func HasVersionFileReferences(ctx context.Context, versionID int64) (bool, error) {
 	return db.GetEngine(ctx).Get(&PackageFile{