finalize #2024
[fr] follow #2031, 80b1ec4c, 57288770
Add example of custom provider near other method types.

Refs cakephp/cakephp#5221
Update es and fr docs for custom validation providers.
Reorder some sections.

I think the new ordering makes more sense when reading the document in
a first run context.
Document and add an example for setAction()
Merge pull request #2035 from cakephp/controller-cleanup

Reorder some sections.