Basic Plaid Integration (#1433)

* Basic plaid data model and linking

* Remove institutions, add plaid items

* Improve schema and Plaid provider

* Add webhook verification sketch

* Webhook verification

* Item accounts and balances sync setup

* Provide test encryption keys

* Fix test

* Only provide encryption keys in prod

* Try defining keys in test env

* Consolidate account sync logic

* Add back plaid account initialization

* Plaid transaction sync

* Sync UI overhaul for Plaid

* Add liability and investment syncing

* Handle investment webhooks and process current day holdings

* Remove logs

* Remove "all" period select for performance

* fix amount calc

* Remove todo comment

* Coming soon for investment historical data

* Document Plaid configuration

* Listen for holding updates

app/models/provider/plaid_sandbox.rb

@@ -0,0 +1,28 @@
+class Provider::PlaidSandbox < Provider::Plaid
+  attr_reader :client
+
+  def initialize
+    @client = create_client
+  end
+
+  def fire_webhook(item, type: "TRANSACTIONS", code: "SYNC_UPDATES_AVAILABLE")
+    client.sandbox_item_fire_webhook(
+      Plaid::SandboxItemFireWebhookRequest.new(
+        access_token: item.access_token,
+        webhook_type: type,
+        webhook_code: code,
+      )
+    )
+  end
+
+  private
+    def create_client
+      raise "Plaid sandbox is not supported in production" if Rails.env.production?
+
+      api_client = Plaid::ApiClient.new(
+        Rails.application.config.plaid
+      )
+
+      Plaid::PlaidApi.new(api_client)
+    end
+end