add param data to param pre_save method call

At the moment, it is currently impossible to get the parameter data in the custom pre_save method when creating a field from the API.
This is better.
There we go!
missed one
Adding a description to page_types

Addresses: https://github.com/pyrocms/pyrocms/issues/2278

Includes small changes in the controller, model and views. Also
includes an updated table structure in details.php, as well as a
migration file to add the description field to existing installations.
Missed a line

Missed a line earlier during copying edits to this branch
#2286 - Update child pages when slug is changed
Fix: return empty when a page is not available in the db

The get method of the page model used to return empty on a missing
page.

Currently it returns an object with a variable called
stream_entry_found, which is added to the page object by the get method
itself.

This causes an issue with the edit method in the pages admin
controller. Quite possibly it causes issues elsewhere too.
Update README.md
Added `{{ url:uri_string }}`
Merge pull request #2310 from chadwithuhc/add/uri_string-plugin-method

Added `{{ url:uri_string }}`
Merge pull request #2301 from Solinx/2.2/dev/page_m_get

Fix: return empty when a page is not available in the db
Merge pull request #2299 from mfrost503/2.2/develop

Addresses: #2286, updating the child pages when a parent slug is updated
translations for module addons
Hungarian translation

Filling the gaps in the hungarian translation
Merge pull request #2316 from kbb84/2.2/develop

Hungarian translation
Merge pull request #2315 from khalil-tabbal/2.2/develop

french translations for module addons
Merge pull request #2309 from yckart/patch-1

Update README.md
Merge pull request #2297 from Solinx/2.2/dev/page_type_description

Adding a description to page_types
Adding simple get by URI in pages_m model.

Some upcoming additions will make use of this. It allows you to use the 'get by uri' logic without having to get all the entry data and other items associated with a page (i.e., the page type).