Take AR affixes into account for AStorage models

All of ActiveStorage database modeltable nameshave been hard coded.
Therefore, ActiveRecord::Base.(prefix|suffix) were not taken into
consideration. To fix this we remove the hard coded lines. But then we
need to also override an internal method for specifying the prefix
because of a mystical ActiveRecord/ActiveStorage sync issue
(Suffix does not appear to have the issue)

Some tests were refactored to remove hard coded table name references,
making ActiveStorage test suite compatible with ActiveRecord config.

Author: chaadow

activestorage/CHANGELOG.md

@@ -1,3 +1,8 @@
+*   Fix all Active Storage database related models to respect
+    `ActiveRecord::Base.table_name_prefix` configuration.
+
+    *Chedli Bourguiba*
+
 *   Fix `ActiveStorage::Representations::ProxyController` not returning the proper
     preview image variant for previewable files.
 

activestorage/app/models/active_storage/attachment.rb

@@ -18,8 +18,6 @@
 #   # preloads blobs and variant records (if using `ActiveStorage.track_variants`)
 #   User.first.avatars.with_all_variant_records
 class ActiveStorage::Attachment < ActiveStorage::Record
-  self.table_name = "active_storage_attachments"
-
   ##
   # :method:
   #

activestorage/app/models/active_storage/blob.rb

@@ -17,8 +17,6 @@
 # update a blob's metadata on a subsequent pass, but you should not update the key or change the uploaded file.
 # If you need to create a derivative or otherwise change the blob, simply create a new blob and purge the old one.
 class ActiveStorage::Blob < ActiveStorage::Record
-  self.table_name = "active_storage_blobs"
-
   MINIMUM_TOKEN_LENGTH = 28
 
   has_secure_token :key, length: MINIMUM_TOKEN_LENGTH

activestorage/app/models/active_storage/variant_record.rb

@@ -1,8 +1,6 @@
 # frozen_string_literal: true
 
 class ActiveStorage::VariantRecord < ActiveStorage::Record
-  self.table_name = "active_storage_variant_records"
-
   belongs_to :blob
   has_one_attached :image
 end

activestorage/test/migrations_test.rb

@@ -53,7 +53,7 @@ def rerun_migration
     end
 
     def active_storage_tables
-      [:active_storage_blobs, :active_storage_attachments, :active_storage_variant_records]
+      @active_storage_tables ||= ActiveStorage::Record.descendants.map { |klass| klass.table_name.to_sym }
     end
 
     def primary_key(table)