Allow user to add buy and sell trade transactions for investment accounts (#1066)

* Consolidate modal form structure into partial + helper

* Scaffold out trade transaction form

* Normalize translations

* Add buy and sell trade form with tests

* Move entryable lists to dedicated controllers

* Delegate entry group contents rendering

* More cleanup

* Extract transaction and valuation update logic from entries controller

* Delegate edit and show actions to entryables

* Trade builder

* Update paths for transaction updates

app/controllers/account/valuations_controller.rb

@@ -0,0 +1,35 @@
+class Account::ValuationsController < ApplicationController
+  layout :with_sidebar
+
+  before_action :set_account
+
+  def new
+    @entry = @account.entries.account_valuations.new(entryable_attributes: {})
+  end
+
+  def create
+    @entry = @account.entries.account_valuations.new(entry_params.merge(entryable_attributes: {}))
+
+    if @entry.save
+      @entry.sync_account_later
+      redirect_to account_valuations_path(@account), notice: t(".success")
+    else
+      flash[:alert] = @entry.errors.full_messages.to_sentence
+      redirect_to account_path(@account)
+    end
+  end
+
+  def index
+    @entries = @account.entries.account_valuations.reverse_chronological
+  end
+
+  private
+
+    def set_account
+      @account = Current.family.accounts.find(params[:account_id])
+    end
+
+    def entry_params
+      params.require(:account_entry).permit(:name, :date, :amount, :currency)
+    end
+end