test: share the first-page and clock helpers

writeFirstPage answers paged listings in app and services tests,
testNow replaces the copied clock, withoutANSI the second color
stripper, and the single-entry table test becomes a plain test.

Signed-off-by: bircni <bircni@icloud.com>

internal/app/label_options_test.go

@@ -96,11 +96,7 @@ func TestLabelsByName(t *testing.T) {
 	server := newAuthenticatedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		switch r.Method + " " + r.URL.Path {
 		case "GET /api/v1/repos/alice/project/labels":
-			if r.URL.Query().Get("page") != "1" {
-				_, _ = w.Write([]byte(`[]`))
-				return
-			}
-			_, _ = w.Write([]byte(labels))
+			writeFirstPage(w, r, labels)
 		default:
 			changed = append(changed, r.Method+" "+r.URL.Path+" "+requestFields(t, r, "name", "color", "description"))
 			if r.Method == http.MethodDelete {