Fix browser back button to restore scroll state

Removes the url parameter that was used to identify the card to scroll
to and instead use the id from the internal model.

modules/webapp/src/main/elm/Page.elm

@@ -24,7 +24,7 @@ import Util.Maybe
 
 
 type Page
-    = HomePage (Maybe String)
+    = HomePage
     | LoginPage (Maybe Page)
     | ManageDataPage
     | CollectiveSettingPage
@@ -39,7 +39,7 @@ type Page
 isSecured : Page -> Bool
 isSecured page =
     case page of
-        HomePage _ ->
+        HomePage ->
             True
 
         LoginPage _ ->
@@ -88,7 +88,7 @@ loginPage p =
 pageName : Page -> String
 pageName page =
     case page of
-        HomePage _ ->
+        HomePage ->
             "Home"
 
         LoginPage _ ->
@@ -147,10 +147,7 @@ uploadId page =
 pageToString : Page -> String
 pageToString page =
     case page of
-        HomePage (Just id) ->
-            "/app/home?item=" ++ id
-
-        HomePage Nothing ->
+        HomePage ->
             "/app/home"
 
         LoginPage referer ->
@@ -232,8 +229,8 @@ parser =
     oneOf
         [ Parser.map HomePage
             (oneOf
-                [ Parser.top <?> itemQuery
-                , s pathPrefix </> s "home" <?> itemQuery
+                [ Parser.top
+                , s pathPrefix </> s "home"
                 ]
             )
         , Parser.map LoginPage (s pathPrefix </> s "login" <?> pageQuery)
@@ -271,8 +268,3 @@ pageQuery =
     in
     Query.string "r"
         |> Query.map parsePage
-
-
-itemQuery : Query.Parser (Maybe String)
-itemQuery =
-    Query.string "item"