Bridge: make some headers submissions free (#4102)

supersedes https://github.com/paritytech/parity-bridges-common/pull/2873

Draft because of couple of TODOs:
- [x] fix remaining TODOs;
- [x] double check that all changes from
https://github.com/paritytech/parity-bridges-common/pull/2873 are
correctly ported;
- [x] create a separate PR (on top of that one or a follow up?) for
https://github.com/paritytech/polkadot-sdk/tree/sv-try-new-bridge-fees;
- [x] fix compilation issues (haven't checked, but there should be
many).

---------

Co-authored-by: Adrian Catangiu <adrian@parity.io>

bridges/bin/runtime-common/Cargo.toml

@@ -16,6 +16,7 @@ hash-db = { version = "0.16.0", default-features = false }
 log = { workspace = true }
 scale-info = { version = "2.11.1", default-features = false, features = ["derive"] }
 static_assertions = { version = "1.1", optional = true }
+tuplex = { version = "0.1", default-features = false }
 
 # Bridge dependencies
 
@@ -82,6 +83,7 @@ std = [
 	"sp-runtime/std",
 	"sp-std/std",
 	"sp-trie/std",
+	"tuplex/std",
 	"xcm-builder/std",
 	"xcm/std",
 ]