Fix the confusingly named and inverted logic of "no_attachment_links"

The setting is now simply "attachment_links" and the boolean value does
what you expect. A double negative is never possible and describing the
functionality is no longer a philospher's worst nightmare.

test/tasks/config_test.exs

@@ -145,7 +145,7 @@ defmodule Mix.Tasks.Pleroma.ConfigTest do
           mrf_transparency_exclusions: [],
           autofollowed_nicknames: [],
           max_pinned_statuses: 1,
-          no_attachment_links: true,
+          attachment_links: false,
           welcome_user_nickname: nil,
           welcome_message: nil,
           max_report_comment_size: 1000,
@@ -190,7 +190,7 @@ defmodule Mix.Tasks.Pleroma.ConfigTest do
         end
 
       assert file ==
-               "#{header}\n\nconfig :pleroma, :instance,\n  name: \"Pleroma\",\n  email: \"example@example.com\",\n  notify_email: \"noreply@example.com\",\n  description: \"A Pleroma instance, an alternative fediverse server\",\n  limit: 5000,\n  chat_limit: 5000,\n  remote_limit: 100_000,\n  upload_limit: 16_000_000,\n  avatar_upload_limit: 2_000_000,\n  background_upload_limit: 4_000_000,\n  banner_upload_limit: 4_000_000,\n  poll_limits: %{\n    max_expiration: 31_536_000,\n    max_option_chars: 200,\n    max_options: 20,\n    min_expiration: 0\n  },\n  registrations_open: true,\n  federating: true,\n  federation_incoming_replies_max_depth: 100,\n  federation_reachability_timeout_days: 7,\n  federation_publisher_modules: [Pleroma.Web.ActivityPub.Publisher],\n  allow_relay: true,\n  rewrite_policy: Pleroma.Web.ActivityPub.MRF.NoOpPolicy,\n  public: true,\n  quarantined_instances: [],\n  managed_config: true,\n  static_dir: \"instance/static/\",\n  allowed_post_formats: [\"text/plain\", \"text/html\", \"text/markdown\", \"text/bbcode\"],\n  mrf_transparency: true,\n  mrf_transparency_exclusions: [],\n  autofollowed_nicknames: [],\n  max_pinned_statuses: 1,\n  no_attachment_links: true,\n  welcome_user_nickname: nil,\n  welcome_message: nil,\n  max_report_comment_size: 1000,\n  safe_dm_mentions: false,\n  healthcheck: false,\n  remote_post_retention_days: 90,\n  skip_thread_containment: true,\n  limit_to_local_content: :unauthenticated,\n  user_bio_length: 5000,\n  user_name_length: 100,\n  max_account_fields: 10,\n  max_remote_account_fields: 20,\n  account_field_name_length: 512,\n  account_field_value_length: 2048,\n  external_user_synchronization: true,\n  extended_nickname_format: true,\n  multi_factor_authentication: [\n    totp: [digits: 6, period: 30],\n    backup_codes: [number: 2, length: 6]\n  ]\n"
+               "#{header}\n\nconfig :pleroma, :instance,\n  name: \"Pleroma\",\n  email: \"example@example.com\",\n  notify_email: \"noreply@example.com\",\n  description: \"A Pleroma instance, an alternative fediverse server\",\n  limit: 5000,\n  chat_limit: 5000,\n  remote_limit: 100_000,\n  upload_limit: 16_000_000,\n  avatar_upload_limit: 2_000_000,\n  background_upload_limit: 4_000_000,\n  banner_upload_limit: 4_000_000,\n  poll_limits: %{\n    max_expiration: 31_536_000,\n    max_option_chars: 200,\n    max_options: 20,\n    min_expiration: 0\n  },\n  registrations_open: true,\n  federating: true,\n  federation_incoming_replies_max_depth: 100,\n  federation_reachability_timeout_days: 7,\n  federation_publisher_modules: [Pleroma.Web.ActivityPub.Publisher],\n  allow_relay: true,\n  rewrite_policy: Pleroma.Web.ActivityPub.MRF.NoOpPolicy,\n  public: true,\n  quarantined_instances: [],\n  managed_config: true,\n  static_dir: \"instance/static/\",\n  allowed_post_formats: [\"text/plain\", \"text/html\", \"text/markdown\", \"text/bbcode\"],\n  mrf_transparency: true,\n  mrf_transparency_exclusions: [],\n  autofollowed_nicknames: [],\n  max_pinned_statuses: 1,\n  attachment_links: false,\n  welcome_user_nickname: nil,\n  welcome_message: nil,\n  max_report_comment_size: 1000,\n  safe_dm_mentions: false,\n  healthcheck: false,\n  remote_post_retention_days: 90,\n  skip_thread_containment: true,\n  limit_to_local_content: :unauthenticated,\n  user_bio_length: 5000,\n  user_name_length: 100,\n  max_account_fields: 10,\n  max_remote_account_fields: 20,\n  account_field_name_length: 512,\n  account_field_value_length: 2048,\n  external_user_synchronization: true,\n  extended_nickname_format: true,\n  multi_factor_authentication: [\n    totp: [digits: 6, period: 30],\n    backup_codes: [number: 2, length: 6]\n  ]\n"
     end
   end
 end

test/web/common_api/common_api_utils_test.exs

@@ -575,11 +575,11 @@ defmodule Pleroma.Web.CommonAPI.UtilsTest do
   end
 
   describe "maybe_add_attachments/3" do
-    test "returns parsed results when no_links is true" do
+    test "returns parsed results when attachment_links is false" do
       assert Utils.maybe_add_attachments(
                {"test", [], ["tags"]},
                [],
-               true
+               false
              ) == {"test", [], ["tags"]}
     end
 
@@ -589,7 +589,7 @@ defmodule Pleroma.Web.CommonAPI.UtilsTest do
       assert Utils.maybe_add_attachments(
                {"test", [], ["tags"]},
                [attachment],
-               false
+               true
              ) == {
                "test<br><a href=\"SakuraPM.png\" class='attachment'>SakuraPM.png</a>",
                [],