vendor: add github.com/Azure/go-ansiterm for --progress on Windows support

vendor/github.com/Azure/go-ansiterm/ground_state.go

@@ -0,0 +1,24 @@
+package ansiterm
+
+type groundState struct {
+	baseState
+}
+
+func (gs groundState) Handle(b byte) (s state, e error) {
+	gs.parser.context.currentChar = b
+
+	nextState, err := gs.baseState.Handle(b)
+	if nextState != nil || err != nil {
+		return nextState, err
+	}
+
+	switch {
+	case sliceContains(printables, b):
+		return gs, gs.parser.print()
+
+	case sliceContains(executors, b):
+		return gs, gs.parser.execute()
+	}
+
+	return gs, nil
+}