feat: Google OAuth for login & signup (#6346)

This PR adds Google OAuth for all existing users, allowing users to log in or sign up via their Google account.

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Co-authored-by: Pranav Raj S <pranav@chatwoot.com>
Co-authored-by: Fayaz Ahmed <15716057+fayazara@users.noreply.github.com>
Co-authored-by: Sojan <sojan@pepalo.com>

Gemfile.lock

@@ -472,9 +472,17 @@ GEM
       hashie (>= 3.4.6)
       rack (>= 2.2.3)
       rack-protection
+    omniauth-google-oauth2 (1.1.1)
+      jwt (>= 2.0)
+      oauth2 (~> 2.0.6)
+      omniauth (~> 2.0)
+      omniauth-oauth2 (~> 1.8.0)
     omniauth-oauth2 (1.8.0)
       oauth2 (>= 1.4, < 3)
       omniauth (~> 2.0)
+    omniauth-rails_csrf_protection (1.0.1)
+      actionpack (>= 4.2)
+      omniauth (~> 2.0)
     openssl (3.1.0)
     orm_adapter (0.5.0)
     os (1.1.4)
@@ -810,7 +818,10 @@ DEPENDENCIES
   net-pop
   net-smtp
   newrelic_rpm
+  omniauth
+  omniauth-google-oauth2
   omniauth-oauth2
+  omniauth-rails_csrf_protection (~> 1.0)
   pg
   pg_search
   procore-sift