Fix typos in sources: operater, tranform, neccessary, trainig (#14907)
### Description
While browsing the sources I found several typos here and there.
I collected them to a single PR and fixed them.
Namely these typos are: operater, tranform, neccessary, trainig.
After fixing none of them was found anymore:
$ git grep "operater"
$ git grep "tranform"
$ git grep "neccessary"
$ git grep "trainig"
$
### Motivation and Context
Since some of the typos are in example notebooks and markdown files,
users can see them.