Provide after assign event for ngrest plugins

[nadar]

In order to secure encode data for model usage the after find event will encode data in text and textarea plugins. When data is not populated trough database (example creating a new model -> save and access/dump/embed user the model values) the input data is not auto encoded this makes xss injection possible when encoding is not done by yourself inside the application.

In order to prevent this the following events will force encoding of the values:

• after insert
• after update
• after refresh