11255 will add a Ssession Gridfield State manager to CMS 5. This should be the default state manager in CMS 6
Acceptance criteria
Current GridFieldStateManager is deprecated in CMS 5 and remove in CMS 6.
Default configuration is updated to use SessionGridFieldStateManager by default in CMS 6
GridFieldStateManagerInterface is updated to match the signature of SessionGridFieldStateManager
Solution is abstract enough that a third party developer could create their own GridFieldStateManager by implementing the GridFieldStateManagerInterface in CMS 6
If feasible, SilverStripe\Forms\GridField\FormAction\SessionStore is removed in favour of the new API.
11255 will add a Ssession Gridfield State manager to CMS 5. This should be the default state manager in CMS 6
Acceptance criteria
GridFieldStateManageris deprecated in CMS 5 and remove in CMS 6.SessionGridFieldStateManagerby default in CMS 6GridFieldStateManagerInterfaceis updated to match the signature ofSessionGridFieldStateManagerGridFieldStateManagerby implementing theGridFieldStateManagerInterfacein CMS 6SilverStripe\Forms\GridField\FormAction\SessionStoreis removed in favour of the new API.