fix(global): minor cleanups

correction to diagram, protobuff, and remove test function not needed

docs/go-graphsync.puml

@@ -158,7 +158,7 @@ package "go-graphsync" {
   }
 
   object "PackagePublicFunctions" as goGraphsyncPf {
-    New(ctx context.Context, network GraphSyncNetwork, getBlockFunc GetBlockFunc) GraphSync
+    New(ctx context.Context, network GraphSyncNetwork, selectorQuerier SelectorQuerier) GraphSync
   }
 
 }

message/pb/message.proto

@@ -12,7 +12,7 @@ message Message {
     bytes selector = 3; // ipld selector to retrieve
     bytes extra = 4;    // aux information. useful for other protocols
     int32 priority = 5;	// the priority (normalized). default to 1
-    bool  cancel = 7;   // whether this cancels a request
+    bool  cancel = 6;   // whether this cancels a request
   }
 
   message Response {

testselector/testselector.go

@@ -106,12 +106,6 @@ func MockDecodeSelectionResponseFunc(data []byte) gsselector.SelectionResponse {
 	return newNode(data)
 }
 
-// MockDecodeRootNodeFunc decodes raw data to a type that satisfies an
-// IPLD node interface
-func MockDecodeRootNodeFunc(data []byte) ipld.Node {
-	return newNode(data)
-}
-
 // GenerateSelector returns a new mock Selector
 func GenerateSelector() gsselector.Selector {
 	node := newNode(randomBytes(blockSize, seedSeq))