First version of new ui based on tailwind

This drops fomantic-ui as css toolkit and introduces tailwindcss. With
tailwind there are no predefined components, but it's very easy to
create those. So customizing the look&feel is much simpler, most of
the time no additional css is needed.

This requires a complete rewrite of the markup + styles. Luckily all
logic can be kept as is. The now old ui is not removed, it is still
available by using a request header `Docspell-Ui` with a value of `1`
for the old ui and `2` for the new ui.

Another addition is "dev mode", where docspell serves assets with a
no-cache header, to disable browser caching. This makes developing a
lot easier.

modules/webapp/src/main/elm/Comp/PasswordInput.elm

@@ -4,11 +4,13 @@ module Comp.PasswordInput exposing
     , init
     , update
     , view
+    , view2
     )
 
 import Html exposing (..)
 import Html.Attributes exposing (..)
 import Html.Events exposing (onClick, onInput)
+import Styles as S
 import Util.Maybe
 
 
@@ -72,3 +74,58 @@ view pw model =
             ]
             []
         ]
+
+
+
+--- View2
+
+
+view2 : Maybe String -> Bool -> Model -> Html Msg
+view2 pw isError model =
+    div [ class "relative" ]
+        [ div [ class S.inputIcon ]
+            [ i
+                [ class "fa"
+                , if model.show then
+                    class "fa-lock-open"
+
+                  else
+                    class "fa-lock"
+                ]
+                []
+            ]
+        , input
+            [ type_ <|
+                if model.show then
+                    "text"
+
+                else
+                    "password"
+            , name "passw1"
+            , autocomplete False
+            , onInput SetPassword
+            , Maybe.withDefault "" pw |> value
+            , class ("pl-10 pr-10 py-2 rounded" ++ S.textInput)
+            , class <|
+                if isError then
+                    S.inputErrorBorder
+
+                else
+                    ""
+            , placeholder "Password"
+            ]
+            []
+        , a
+            [ class S.inputLeftIconLink
+            , class <|
+                if isError then
+                    S.inputErrorBorder
+
+                else
+                    ""
+            , onClick (ToggleShow pw)
+            , href "#"
+            ]
+            [ i [ class "fa fa-eye" ] []
+            ]
+        ]