STYLE: Remove `p->Initialize()` calls directly after `p = T::New()`

[N-Dekker]

For any ITK type T, T::New() does already initialize the object it returns.

Using Notepad++, Replace in Files, doing:

Find what:  (\w+)([ ]+= .+::New\(\);)\r\n[\r\n]* [ ]+\1->Initialize\(\);
Replace with:  $1$2
Filters: itk*.* !+\test
Directory: D:\src\ITK\Modules
[v] Match case
(*) Regular expression

Manually removed an obsolete comment saying Clear elements.