feat(milestone): milestone tables, views, forms and one selection model

milestone view printed the list row, and milestone list hid the due date
and progress. milestone list now shows ID TITLE [STATE] DUE PROGRESS, open
milestones first and by due date; milestone view shows the state, due
date, progress, description and the milestone's web page (also --web).

Every milestone command addresses milestones by title or ID. Mutations
report ✓ lines: milestone create also prints the new milestone's URL and
takes the title as an argument; close and reopen skip milestones already
in that state; delete names the milestone in its confirmation; milestone
issue add and remove report one line such as "✓ Added #1, #2 to
milestone "v1.0" in alice/x". milestone issue list uses the issue table.
milestone edit without flags on a terminal opens the milestone form with
the current values, and every milestone command completes milestone
titles and has help text with examples.

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

internal/services/comments_test.go

@@ -57,7 +57,7 @@ func TestRemoveMilestoneRejectsDifferentMembership(t *testing.T) {
 		_, _ = w.Write([]byte(`{"milestone":{"id":9}}`))
 	}))
 	service := Issues{Client: client, Repository: "alice/project"}
-	_, err := service.RemoveMilestone(context.Background(), 7, 8)
-	require.ErrorContains(t, err, "not assigned to milestone 8")
+	_, err := service.RemoveMilestone(context.Background(), 7, Milestone{ID: 8, Title: "v1.0"})
+	require.EqualError(t, err, `#7 is not in milestone "v1.0"`)
 	require.Zero(t, mutations)
 }