* Adding MaxEncodedLen for:
* NextConfigDescriptor
* AllowedSlots
* BabeEpochConfiguration
In prepation for adding storage information on pallet babe
* Adding stotage_info to pallet babe
Refactored UNDER_CONSTRUCTION_SEGMENT_LENGTH to become a runtime
parameter MaxSegmentLength
* Reinstate Slice as opposed to Vec
* Refactoring code to make it neater
* Replace `MaxSegmentLength` by
`UNDER_CONSTRUCTION_SEGMENT_LENGTH`
Stop exposing the bounds to the runtime
* Removing extra line
Co-authored-by: thiolliere <gui.thiolliere@gmail.com>