fix event embed filters + new clipboard mixin

assets/clipboard.js

@@ -0,0 +1,18 @@
+export default {
+  methods: {
+    clipboard (str, msg = 'common.copied') {
+      try {
+        navigator.clipboard.writeText(str)
+      } catch (e) {
+        const el = document.createElement('textarea')
+        el.addEventListener('focusin', e => e.stopPropagation())
+        el.value = str
+        document.body.appendChild(el)
+        el.select()
+        document.execCommand('copy')
+        document.body.removeChild(el)
+      }
+      this.$root.$message(msg)
+    }
+  }
+}

assets/style.less

@@ -120,4 +120,9 @@ li {
 
 .cursorPointer {
   cursor: pointer;
+}
+
+pre {
+  white-space: break-spaces;
+  font-size: 13px;
 }