Use the fast_blank gem

See https://github.com/rails/rails/pull/24658#issuecomment-212651965

Gemfile

@@ -233,6 +233,9 @@ gem 'charlock_holmes', '~> 0.7.5'
 # Faster JSON
 gem 'oj', '~> 2.17.4'
+# Faster blank
+gem 'fast_blank'
+
 # Parse time & duration
 gem 'chronic', '~> 0.10.2'
 gem 'chronic_duration', '~> 0.10.6'

Gemfile.lock

@@ -207,6 +207,7 @@ GEM
     faraday_middleware-multi_json (0.0.6)
       faraday_middleware
       multi_json
+    fast_blank (1.0.0)
     fast_gettext (1.4.0)
     ffaker (2.4.0)
     ffi (1.9.18)
@@ -1034,6 +1035,7 @@ DEPENDENCIES
   email_spec (~> 1.6.0)
   factory_bot_rails (~> 4.8.2)
   faraday (~> 0.12)
+  fast_blank
   ffaker (~> 2.4)
   flay (~> 2.8.0)
   flipper (~> 0.11.0)

changelogs/unreleased/16468-add-fast-blank.yml

+---
+title: "Add fast-blank"
+merge_request: 16468
+author:
+type: performance