Add Page Titles Everywhere (#177)

Add page titles everywhere

Add global mixin to set page title

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/frontend/pulls/177

src/views/sharing/LinkSharingAuth.vue

@@ -22,6 +22,9 @@
 		created() {
 			this.auth()
 		},
+		mounted() {
+			this.setTitle('Authenticating...')
+		},
 		methods: {
 			auth() {
 				this.$store.dispatch('auth/linkShareAuth', this.$route.params.share)