Start implementing podcast support

front/src/components/audio/ChannelEntries.vue

front/src/components/audio/PlayButton.vue

front/src/components/audio/podcast/MobileRow.vue

front/src/components/audio/podcast/Modal.vue

front/src/components/audio/podcast/Row.vue

front/src/components/audio/podcast/Table.vue

front/src/components/audio/track/MobileRow.vue

front/src/components/audio/track/Modal.vue

front/src/components/audio/track/Row.vue

front/src/components/library/AlbumDetail.vue

front/src/style/components/_track_table.scss

front/src/views/channels/DetailOverview.vue