Handle commands without automatic reaction responses

Introduce `ErrCommandNoReactions` to allow commands to opt out of success reactions. Adjust bot behavior to respect this error and prevent reactions when applicable, ensuring cleaner and more controlled responses. Add error handling and safeguard workers against panics.

sites/wegmans/wegmans.go

@@ -36,6 +36,7 @@ func deferClose(c io.Closer) {
 }
 
 func (c Config) GetItemPrice(ctx context.Context, b extractor.Browser, u *url.URL) (Item, error) {
+
 	if b == nil {
 		return Item{}, ErrNilBrowser
 	}