Fixed resolve of multiple inherited constructors for new-style MRO (PY-9080)

Integrated a C3 MRO algorithm implementation into PyClass.getAncestorTypes().

python/psi-api/src/com/jetbrains/python/psi/PyClass.java

@@ -122,17 +122,6 @@ public interface PyClass extends PsiNameIdentifierOwner, PyStatement, NameDefine
   @NotNull
   List<PyClassLikeType> getAncestorTypes(@NotNull TypeEvalContext context);
 
-  /**
-   * Return the method resolution order list for this class.
-   * <br/>
-   * see http://www.python.org/download/releases/2.3/mro/
-   * <br/>
-   * <i>Note: the list begins with this class.</i> It ends with the builtin 'object'.
-   * If class hierarchy is incorrect, e.g. badly looped, assertions may fail in implementation.
-   * @return list of classes in method resolution order for this class, at least one element long.
-   */
-  @NotNull List<PyClass> getMRO();
-
   /**
    * Scan properties in order of definition, until processor returns true for one of them.
    * @param processor to check properties