Revert "fix(model): Return empty PURL when package name is empty"

This reverts commit 4af9208. It is not needed anymore as Pub SDK packages
are being filtered out before PURL construction.

Signed-off-by: Sebastian Schuberth <sebastian@doubleopen.org>

Author: sschuberth

model/src/main/kotlin/utils/PurlExtensions.kt

@@ -90,10 +90,6 @@ fun Identifier.toPurl(qualifiers: Map<String, String> = emptyMap(), subpath: Str
     val namespace = combined.substringBeforeLast('/').trim('/').takeIf { it.isNotEmpty() }
     val name = combined.substringAfterLast('/').trim('/')
 
-    // Avoid a `MalformedPackageURLException` and behave like for `Identifier.EMPTY` in case of exotic packages like
-    // Pub SDK packages (e.g., sky_engine) where the name is not explicitly set.
-    if (name.isEmpty()) return ""
-
     val normalizedSubpath = if (subpath.isNotEmpty()) {
         subpath.trim('/').split('/')
             .filter { it.isNotEmpty() }