PY-28321 Revert source root order for imports

The commit reverts source root order respect for import statements thus
reopening PY-28321. The reason is that until pkg_resources and pkgutil
namespace packages are not implemented (see PY-16688, PY-23087) the
original fix leads to false positives in projects relying on this
functionality.

As soon as namespace packages support via pkg_resources and pkgutil will
 be implemented the change should be reverted back to close PY-28321.

python/src/com/jetbrains/python/psi/resolve/PyResolveImportUtil.kt

@@ -101,7 +101,8 @@ private fun resolveQualifiedName(name: QualifiedName,
 
   val foreignResults = foreignResults(name, context)
   val pythonResults = listOf(relativeResults,
-                             resolveFromRoots(name, context),
+                             // TODO: replace with resolveFromRoots when namespace package magic features PY-16688, PY-23087 are implemented
+                             resultsFromRoots(name, context),
                              relativeResultsFromSkeletons(name, context)).flatten().distinct()
   val allResults = pythonResults + foreignResults
   val results = if (name.componentCount > 0) findFirstResults(pythonResults, context.module) + foreignResults else allResults

python/testSrc/com/jetbrains/python/PyMultiFileResolveTest.java

@@ -467,7 +467,8 @@ public class PyMultiFileResolveTest extends PyMultiFileResolveTestCase {
   }
 
   // PY-28321
-  public void testImportManySourceRootsReverseRootOrder() {
+  // TODO: The test should be turned on as soon as PY-16688 and PY-23087 are implemented
+  public void ignoreTestImportManySourceRootsReverseRootOrder() {
     myFixture.copyDirectoryToProject("importManySourceRoots", "");
     runWithSourceRoots(Lists.newArrayList(myFixture.findFileInTempDir("root1"), myFixture.findFileInTempDir("root2")), () -> {
       final PsiFile psiFile = myFixture.configureByFile("root1/pkg/a.py");