Scaffold out the UI for individual account page (#461)

* Add `AccountBalance` table for account views

* Scaffold out account UI

* Add D3 line chart scaffolding

* Style fixes

test/fixtures/account_balances.yml

@@ -0,0 +1,13 @@
+# Read about fixtures at https://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+
+one:
+  account: dylan_checking
+  date: 2024-02-12
+  balance: 9.99
+  currency: MyString
+
+two:
+  account: richards_savings
+  date: 2024-02-12
+  balance: 9.99
+  currency: MyString

test/models/account_balance_test.rb

@@ -0,0 +1,7 @@
+require "test_helper"
+
+class AccountBalanceTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end