Add SimpleMDE and Fix Image Paste for Issue/Comment Editor (#9197)

* update #9132 and #8834 - add SimpleMDE for issue and fix image paste for comment editor

* attache tribute to simplemde

* update #9197 force simplemde file input event when backspace press

routers/repo/issue.go

@@ -673,6 +673,7 @@ func ViewIssue(ctx *context.Context) {
 	ctx.Data["RequireHighlightJS"] = true
 	ctx.Data["RequireDropzone"] = true
 	ctx.Data["RequireTribute"] = true
+	ctx.Data["RequireSimpleMDE"] = true
 	renderAttachmentSettings(ctx)
 
 	if err = issue.LoadAttributes(); err != nil {