Prepare for sub to eth relay - part2 (#253)

* fixed PoA contract deploy (granda_authorities call)

* pause if all submitted headers were rejected

* give funds to Bertha and Carlos

* max 1 active PoA transaction in headers sync :(

* display initial header id when deploying PoA contract

* cargo fmt + clipy

* update PoA contract to accept <= 4 Substrate headers at once

* pause submitting headers when contract rejects all new headers + we have active transactions

* fix compilation

* cargo fmt --all

* does_not_select_new_headers_to_submit_when_submit_is_paused

* updated bridge contract

* Update relays/ethereum/src/sync.rs

Co-authored-by: Hernando Castano <HCastano@users.noreply.github.com>

* WiP.

* Submit first incomplete header.

* Finish up test.

* cargo fmt --all

* Remove redundant clone.

* Address review comments.

* cargo fmt --all

* Fix clippy.

Co-authored-by: Hernando Castano <HCastano@users.noreply.github.com>
Co-authored-by: Tomasz Drwięga <tomasz@parity.io>

bridges/relays/ethereum/res/substrate-bridge-abi.json

@@ -69,11 +69,26 @@
 		"inputs": [
 			{
 				"internalType": "bytes",
-				"name": "rawHeader",
+				"name": "rawHeader1",
+				"type": "bytes"
+			},
+			{
+				"internalType": "bytes",
+				"name": "rawHeader2",
+				"type": "bytes"
+			},
+			{
+				"internalType": "bytes",
+				"name": "rawHeader3",
+				"type": "bytes"
+			},
+			{
+				"internalType": "bytes",
+				"name": "rawHeader4",
 				"type": "bytes"
 			}
 		],
-		"name": "importHeader",
+		"name": "importHeaders",
 		"outputs": [],
 		"stateMutability": "nonpayable",
 		"type": "function"
@@ -100,16 +115,31 @@
 		"inputs": [
 			{
 				"internalType": "bytes",
-				"name": "rawHeader",
+				"name": "rawHeader1",
+				"type": "bytes"
+			},
+			{
+				"internalType": "bytes",
+				"name": "rawHeader2",
+				"type": "bytes"
+			},
+			{
+				"internalType": "bytes",
+				"name": "rawHeader3",
+				"type": "bytes"
+			},
+			{
+				"internalType": "bytes",
+				"name": "rawHeader4",
 				"type": "bytes"
 			}
 		],
-		"name": "isIncompleteHeader",
+		"name": "isIncompleteHeaders",
 		"outputs": [
 			{
-				"internalType": "bool",
+				"internalType": "uint256",
 				"name": "",
-				"type": "bool"
+				"type": "uint256"
 			}
 		],
 		"stateMutability": "view",