Display variable referred parameters even when variable doesn't exist in OpenFisca.

src/lib/components/WaterfallView.svelte

@@ -170,10 +170,6 @@
                         sveltekit:noscroll
                         >{decomposition.ux_name ?? decomposition.label}</a
                       >
-                    {:else if variable === undefined}
-                      <!-- Trunk decomposition without variable, in parameters mode => no link -->
-                      <span>{decomposition.ux_name ?? decomposition.label}</span
-                      >
                     {:else}
                       <!-- Trunk decomposition node with parameters, in parameters mode => link -->
                       <a
@@ -264,12 +260,6 @@
                       sveltekit:noscroll
                       >{decomposition.ux_name ?? decomposition.label}</a
                     >
-                  {:else if variable === undefined}
-                    <!-- Leaf decomposition without variable, in parameters mode => no link -->
-                    <span
-                      class="hover:bg-white font-serif overflow-ellipsis overflow-x-hidden hover:overflow-x-visible text-base hover:z-20"
-                      >{decomposition.ux_name ?? decomposition.label}</span
-                    >
                   {:else}
                     <!-- Leaf decomposition node with parameters in parameters mode => link -->
                     <a
@@ -334,18 +324,6 @@
                     >
                       {decomposition.ux_name ?? decomposition.label}
                     </span>
-                  {:else if variable === undefined}
-                    <!-- Leaf decomposition without variable, in parameters mode => no link -->
-                    <span
-                      class="hover:bg-white cursor-pointer font-serif overflow-ellipsis overflow-x-hidden hover:overflow-x-visible text-black hover:text-black text-base hover:underline hover:z-20"
-                      on:click={() => {
-                        if (decomposition.open) {
-                          zoomOut(index)
-                        } else {
-                          zoomIn(index)
-                        }
-                      }}>{decomposition.ux_name ?? decomposition.label}</span
-                    >
                   {:else}
                     <!-- Leaf decomposition node with parameters in parameters mode => link -->
                     <a