Fixes and improvements to the Profile Preview modal (#992)

* Fix: use more reliable navigation method

* Fix: show lightbox over the active modal

* Fix: close the profile preview on navigation

* Factor out UserPreviewLink and add preview behavior to notifications

* Fix postmeta overflow on web

* Fix lint

src/view/shell/index.tsx

@@ -61,7 +61,6 @@ const ShellInner = observer(() => {
           </Drawer>
         </ErrorBoundary>
       </View>
-      <Lightbox />
       <Composer
         active={store.shell.isComposerActive}
         onClose={() => store.shell.closeComposer()}
@@ -71,6 +70,7 @@ const ShellInner = observer(() => {
         quote={store.shell.composerOpts?.quote}
       />
       <ModalsContainer />
+      <Lightbox />
     </>
   )
 })