Add security prices provider (Synth integration) (#1039)

* User tickers as primary lookup symbol instead of isin

* Add security price provider

* Fetch security prices in bulk to improve sync performance

* Fetch prices in bulk, better mocking for tests

test/interfaces/security_price_provider_interface_test.rb

@@ -0,0 +1,20 @@
+require "test_helper"
+
+module SecurityPriceProviderInterfaceTest
+  extend ActiveSupport::Testing::Declarative
+
+  test "security price provider interface" do
+    assert_respond_to @subject, :fetch_security_prices
+  end
+
+  test "security price provider response contract" do
+    VCR.use_cassette "synth/security_prices" do
+      response = @subject.fetch_security_prices ticker: "AAPL", start_date: Date.iso8601("2024-01-01"), end_date: Date.iso8601("2024-08-01")
+
+      assert_respond_to response, :prices
+      assert_respond_to response, :success?
+      assert_respond_to response, :error
+      assert_respond_to response, :raw_response
+    end
+  end
+end