FEATURE: Track API and user API requests (#19186)

Adds stats for API and user API requests similar to regular page views.
This comes with a new report to visualize API requests per day like the
consolidated page views one.

spec/integration/request_tracker_spec.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+RSpec.describe 'request tracker' do
+  let(:api_key) do
+    Fabricate(
+      :api_key,
+      user: Fabricate.build(:user),
+      api_key_scopes: [ApiKeyScope.new(resource: 'users', action: 'show')]
+    )
+  end
+
+  let(:user_api_key) do
+    Fabricate(:user_api_key, scopes: [Fabricate.build(:user_api_key_scope, name: 'session_info')])
+  end
+
+  before do
+    CachedCounting.reset
+    CachedCounting.enable
+    ApplicationRequest.enable
+  end
+
+  after do
+    ApplicationRequest.disable
+    CachedCounting.reset
+    CachedCounting.disable
+  end
+
+  context 'when using an api key' do
+    it 'is counted as an API request' do
+      get "/u/#{api_key.user.username}.json", headers: { HTTP_API_KEY: api_key.key }
+      expect(response.status).to eq(200)
+
+      CachedCounting.flush
+      expect(ApplicationRequest.http_total.first.count).to eq(1)
+      expect(ApplicationRequest.http_2xx.first.count).to eq(1)
+      expect(ApplicationRequest.api.first.count).to eq(1)
+    end
+  end
+
+  context 'when using an user api key' do
+    it 'is counted as a user API request' do
+      get '/session/current.json', headers: { HTTP_USER_API_KEY: user_api_key.key }
+      expect(response.status).to eq(200)
+
+      CachedCounting.flush
+      expect(ApplicationRequest.http_total.first.count).to eq(1)
+      expect(ApplicationRequest.http_2xx.first.count).to eq(1)
+      expect(ApplicationRequest.user_api.first.count).to eq(1)
+    end
+  end
+end