Full-text search for authorized statuses (#6423)

* Add full-text search for authorized statuses

- Search API will return statuses that match the query
- Only for logged in users
- Only if you are author of the status,
- Or you were mentioned in it
- Or you favourited or reblogged it
- Configuration over `ES_ENABLED`, `ES_HOST`, `ES_PORT`, `ES_PREFIX`
- Run `rails chewy:deploy` to create & populate index

Fix #5880
Fix #4293
Fix #1152

* Add commented out docker-compose configuration for ES container

* Optimize index import, filter search results

* Add basic normalization to the index

* Add better stemming and normalization to the index

* Skip webfinger request if search query includes both @ and a space

* Fix code style

* Visually separate search result sections

* Fix code style issues

docker-compose.yml

@@ -19,6 +19,17 @@ services:
 #    volumes:
 #      - ./redis:/data
 
+#  es:
+#    restart: always
+#    image: docker.elastic.co/elasticsearch/elasticsearch-oss:6.1.3
+#    environment:
+#      - "ES_JAVA_OPTS=-Xms512m -Xmx512m"
+#    networks:
+#      - internal_network
+#### Uncomment to enable ES persistance
+##    volumes:
+##      - ./elasticsearch:/usr/share/elasticsearch/data
+
   web:
     build: .
     image: gargron/mastodon
@@ -33,6 +44,7 @@ services:
     depends_on:
       - db
       - redis
+#      - es
     volumes:
       - ./public/assets:/mastodon/public/assets
       - ./public/packs:/mastodon/public/packs