Refactor and add securities controller

lib/tradex_web/controllers/security_html/index.html.heex

@@ -0,0 +1,28 @@
+<.header>
+  Listing Securities
+  <:actions>
+    <.link href={~p"/securities/new"}>
+      <.button>New Security</.button>
+    </.link>
+  </:actions>
+</.header>
+
+<.table id="securities" rows={@securities} row_click={&JS.navigate(~p"/securities/#{&1}")}>
+  <:col :let={security} label="Name">{security.name}</:col>
+  <:col :let={security} label="Ticker">{security.ticker}</:col>
+  <:col :let={security} label="Wkn">{security.wkn}</:col>
+  <:col :let={security} label="Isin">{security.isin}</:col>
+  <:col :let={security} label="Expiration date">{security.expiration_date}</:col>
+  <:col :let={security} label="Strike price">{security.strike_price}</:col>
+  <:action :let={security}>
+    <div class="sr-only">
+      <.link navigate={~p"/securities/#{security}"}>Show</.link>
+    </div>
+    <.link navigate={~p"/securities/#{security}/edit"}>Edit</.link>
+  </:action>
+  <:action :let={security}>
+    <.link href={~p"/securities/#{security}"} method="delete" data-confirm="Are you sure?">
+      Delete
+    </.link>
+  </:action>
+</.table>