Use tags from status when adding handlers to hashtag spans in status content (#2344)

* Migrate LinkHelper to kotlin

* Support tags field on statuses

* Use embedded tags list in status instead of text scraping to embed tag click handler.
Fixes #2283

* Make mentions and tags lists nonnullable

* Make LinkHelper.openLink a Context extension method

* Use builtin extension for uri conversion

* More cleanup in LinkHelper

* Add tests for LinkHelper.getDomain

* Unbreak tags in places that don't have a tag list (e.g. profiles)

* Fixup javadoc

app/src/test/java/com/keylesspalace/tusky/db/TimelineDaoTest.kt

@@ -410,6 +410,7 @@ class TimelineDaoTest {
             visibility = Status.Visibility.PRIVATE,
             attachments = "attachments$accountId",
             mentions = "mentions$accountId",
+            tags = "tags$accountId",
             application = "application$accountId",
             reblogServerId = if (reblog) (statusId * 100).toString() else null,
             reblogAccountId = reblogAuthor?.serverId,