Support deleting items from the custom commands history

In the custom commands panel you can now tab to the suggestions and hit 'd' to
delete items from there. Useful if you mistyped a command and don't want it to
appear in your history any more.

pkg/gui/types/common.go

@@ -165,13 +165,14 @@ type CreateMenuOptions struct {
 }
 
 type CreatePopupPanelOpts struct {
-	HasLoader           bool
-	Editable            bool
-	Title               string
-	Prompt              string
-	HandleConfirm       func() error
-	HandleConfirmPrompt func(string) error
-	HandleClose         func() error
+	HasLoader              bool
+	Editable               bool
+	Title                  string
+	Prompt                 string
+	HandleConfirm          func() error
+	HandleConfirmPrompt    func(string) error
+	HandleClose            func() error
+	HandleDeleteSuggestion func(int) error
 
 	FindSuggestionsFunc func(string) []*Suggestion
 	Mask                bool
@@ -193,8 +194,9 @@ type PromptOpts struct {
 	FindSuggestionsFunc func(string) []*Suggestion
 	HandleConfirm       func(string) error
 	// CAPTURE THIS
-	HandleClose func() error
-	Mask        bool
+	HandleClose            func() error
+	HandleDeleteSuggestion func(int) error
+	Mask                   bool
 }
 
 type MenuSection struct {