Change how hashtags are normalized (#18795)

app/controllers/admin/tags_controller.rb

app/controllers/api/v1/featured_tags_controller.rb

app/controllers/settings/featured_tags_controller.rb

app/javascript/mastodon/actions/compose.js

app/lib/ascii_folding.rb

app/lib/hashtag_normalizer.rb

app/models/account.rb

app/models/custom_filter.rb

app/models/custom_filter_keyword.rb

app/models/featured_tag.rb

app/models/tag.rb

app/serializers/activitypub/hashtag_serializer.rb

app/serializers/rest/featured_tag_serializer.rb

app/serializers/rest/tag_serializer.rb

app/views/accounts/show.html.haml

app/views/accounts/show.rss.ruby

app/views/admin/tags/show.html.haml

app/views/admin/trends/tags/_tag.html.haml

app/views/admin_mailer/_new_trending_tags.text.erb

app/views/settings/featured_tags/index.html.haml