Define missing hooks in list

[zuk3975]

Questions	Answers
Branch?	8.x
Description?	Couldn't find where hook displayCheckoutBeforeConfirmation is executed, only found it defined in hook.xml
Fixed ticket?	https://github.com/PrestaShop/docs/issues/1447

[zuk3975]

Notes:

• actionGetAdminToolbarButtons - unnecessary & in params. That is a collection object, so im pretty sure ampersand is useless here.
• it would be nice to use psalm notations to define array structures in hook params. (probably in dedicated pr) E.g.

'previous_search_panels' => (SearchPanelInterface[]) $searchPanels,

or

'previous_search_panels' => (array<int, SearchPanelInterface>) $searchPanels,

[matks]

Thank you @zuk3975