feat(comment): comment on issues and pull requests the gh way

tea issue comment 12 --body "LGTM" failed with "unknown flag: --body"; the
comment had to be created with issue comment create. issue comment and
pr comment now take the issue or pull request and -b/-F/-e directly,
plus --edit-last and --delete-last for your last comment. The
subcommands stay, create is also add, and a misspelled subcommand
suggests the right one.

Comments are written in the configured editor or a multi-line
"Comment (markdown):" field, which edits start from the current text,
without a confirmation afterwards. The new comment's URL goes to stdout
with a ✓ line; deletes ask "Delete comment 81 on alice/x#1?". comment
list shows each comment under a "#79 alice • about 2 hours ago"
heading on a terminal and as key/value blocks when piped, and comment
JSON gains issue_number.

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

internal/app/editor_test.go

@@ -23,6 +23,10 @@ func TestCommentEditorDraftLifecycle(t *testing.T) {
 		t.Run(mode, func(t *testing.T) {
 			requests := 0
 			server := newAuthenticatedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				if r.Method == http.MethodGet {
+					_, _ = w.Write([]byte(`{"number":3,"title":"Crash"}`))
+					return
+				}
 				requests++
 				var options struct{ Body string }
 				require.NoError(t, json.NewDecoder(r.Body).Decode(&options))