app: move system.ClipboardEvent to its own package

API change. Update your code with gofmt rule and goimports:

gofmt -r "system.ClipboardEvent -> clipboard.Event"
goimports

Signed-off-by: Inkeliz <inkeliz@inkeliz.com>
Signed-off-by: Elias Naur <mail@eliasnaur.com>

io/clipboard/clipboard.go

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: Unlicense OR MIT
+
+package clipboard
+
+// Event is generated when the clipboard content is requested.
+type Event struct {
+	Text string
+}
+
+func (Event) ImplementsEvent() {}