Basic Portfolio Views (#1000)

* Add holdings tab to account view

* Basic portfolio UI

* Cleanup

* Handle missing holding data

* Remove synced at (implemented in separate pr)

* translations

* Tweak post sync streams

* Remove stale methods from merge conflict

test/support/securities_test_helper.rb

@@ -0,0 +1,16 @@
+module SecuritiesTestHelper
+  def create_security(symbol, prices:)
+    isin_codes = {
+      "AMZN" => "US0231351067",
+      "NVDA" => "US67066G1040"
+    }
+
+    isin = isin_codes[symbol]
+
+    prices.each do |price|
+      Security::Price.create! isin: isin, date: price[:date], price: price[:price]
+    end
+
+    Security.create! isin: isin, symbol: symbol
+  end
+end