docs: clarify what is available in ctx.BlockHeader() (backport #23394) (#23398)

Co-authored-by: Julien Robert <julien@rbrt.fr>

types/context.go

@@ -92,6 +92,9 @@ func (c Context) CometInfo() comet.Info                         { return c.comet
 func (c Context) HeaderInfo() header.Info                       { return c.headerInfo }
 
 // BlockHeader returns the header by value.
+// Note, only ChainID, Time and Height are always filled by baseapp.
+// In finalize block, the proposer address, validator hash and app hash are also filled.
+// Use CometInfo service and/or the Consensus Keeper for getting more information.
 func (c Context) BlockHeader() cmtproto.Header {
 	return c.header
 }

x/auth/ante/expected_keepers.go

@@ -28,5 +28,6 @@ type FeegrantKeeper interface {
 }
 
 type ConsensusKeeper interface {
+	AppVersion(ctx context.Context) (uint64, error)
 	BlockParams(context.Context) (uint64, uint64, error)
 }

x/auth/ante/testutil/expected_keepers_mocks.go

@@ -194,6 +194,21 @@ func (m *MockConsensusKeeper) EXPECT() *MockConsensusKeeperMockRecorder {
 	return m.recorder
 }
 
+// AppVersion mocks base method.
+func (m *MockConsensusKeeper) AppVersion(ctx context.Context) (uint64, error) {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "AppVersion", ctx)
+	ret0, _ := ret[0].(uint64)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// AppVersion indicates an expected call of AppVersion.
+func (mr *MockConsensusKeeperMockRecorder) AppVersion(ctx interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "AppVersion", reflect.TypeOf((*MockConsensusKeeper)(nil).AppVersion), ctx)
+}
+
 // BlockParams mocks base method.
 func (m *MockConsensusKeeper) BlockParams(arg0 context.Context) (uint64, uint64, error) {
 	m.ctrl.T.Helper()