Add set custom header to Seedling Runtime (#846)

* before adding seedling client side

* seedling runtime compiles

* create seedling spec script added

* seedling node & BaseCallFilter fixes

* update AllPalets

* formatting

* CallFilter + SignedExtra + AccountData fix

* XCM removed

* cleanup

* solo-to-para pallet added & before testing

* fix runtime upgrade method

* soloToPara pallet + set header

* clean up

* clean up 2

* signed extension check sudo added

* fmt + cleanup

* Refac code and fixes

* fmt

* Update pallets/solo-to-para/src/lib.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Update pallets/solo-to-para/src/lib.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Update pallets/solo-to-para/src/lib.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* small fixes

* OnValidationData used

* small changes

* Update pallets/solo-to-para/src/lib.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Update pallets/solo-to-para/src/lib.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Update pallets/solo-to-para/src/lib.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* OnValidationData replaced by OnSystemEvent

* fmt + cargo fix

* disable-default-bootnodes for seedling script

Co-authored-by: Ricardo Rius <ricardo@parity.io>
Co-authored-by: Ricardo Rius <9488369+riusricardo@users.noreply.github.com>
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>