[web] Use named route for podcast page

Switching to named routes in order to reduce future maintenance.

web-src/src/components/ListAlbums.vue

@@ -105,7 +105,7 @@ export default {
     open_album(album) {
       this.selected_album = album
       if (this.media_kind_resolved === 'podcast') {
-        this.$router.push({ path: '/podcasts/' + album.id })
+        this.$router.push({ name: 'podcast', params: { id: album.id } })
       } else if (this.media_kind_resolved === 'audiobook') {
         this.$router.push({ name: 'audiobook', params: { id: album.id } })
       } else {

web-src/src/components/ModalDialogAlbum.vue

@@ -158,7 +158,7 @@ export default {
     open_album() {
       this.$emit('close')
       if (this.media_kind_resolved === 'podcast') {
-        this.$router.push({ path: '/podcasts/' + this.album.id })
+        this.$router.push({ name: 'podcast', params: { id: this.album.id } })
       } else if (this.media_kind_resolved === 'audiobook') {
         this.$router.push({ name: 'audiobook', params: { id: this.album.id } })
       } else {

web-src/src/components/ModalDialogQueueItem.vue

@@ -209,7 +209,10 @@ export default {
 
     open_album() {
       if (this.media_kind === 'podcast') {
-        this.$router.push({ path: '/podcasts/' + this.item.album_id })
+        this.$router.push({
+          name: 'podcast',
+          params: { id: this.item.album_id }
+        })
       } else if (this.media_kind === 'audiobook') {
         this.$router.push({
           name: 'audiobook',

web-src/src/components/ModalDialogTrack.vue

@@ -243,7 +243,10 @@ export default {
     open_album() {
       this.$emit('close')
       if (this.track.media_kind === 'podcast') {
-        this.$router.push({ path: '/podcasts/' + this.track.album_id })
+        this.$router.push({
+          name: 'podcast',
+          params: { id: this.track.album_id }
+        })
       } else if (this.track.media_kind === 'audiobook') {
         this.$router.push({
           name: 'audiobook',