Change: Remove deprecated components

To focus on the quality of the currently relevant components and to reduce bundle size, 
we are dropping a bunch of deprecated components from our design system.

List of removed components, for reference:

- OcActionDrop.vue
- OcAppLayout.vue
- OcAutocomplete.vue
- OcDatepicker.vue
- OcDisclosureDrop.vue
- OcNav.vue
- OcNavItem.vue
- OcNavbar.vue
- OcTabItem.vue
- OcTabbed.vue
- OcTabbedPanel.vue
- OcTabbedTab.vue
- OcTabs.vue
- OcTopBar.vue
- OcUser.vue
- _OcNavbarItem.vue
- _OcSidebarNavDivider.vue
- _OcSidebarNavHeader.vue
- _OcTopBarItem.vue
- _OcTopBarLogo.vue

https://github.com/owncloud/owncloud-design-system/pull/1545
