Move blocking work off the main thread and fix threading races (#4068)

* Defer startup work until first use

* Move cover work off the main thread

* Make tracker calls main-safe and token refresh thread-safe

Kitsu, Shikimori and MangaBaka refresh their token under a lock like
MAL, so parallel calls no longer refresh it twice.

* Fix extension threading and make installs cancellable

The store service read response bodies on Main, which failed with
NetworkOnMainThreadException for http stores.

* Move reader work off the main thread and save progress in order

* Serialize the downloader and fix download threading

* Stop blocking on WorkManager status queries

Also removes NotificationReceiver's open chapter action: nothing sends
it, and its handler used runBlocking.

* Start migration jobs on the migrator's dispatcher

They started undispatched, so each ran on the caller's thread until its
first suspension.

* Run screen and view model work on fitting dispatchers

* Launch work that outlives a screen on the app scope

A launch on another dispatcher is dropped if the screen closes before it
starts, which dialogs that dismiss right away often do. Only the UI
follow-up stays on viewModelScope.

* Remove the coroutine helper extensions

They hid which dispatcher and scope a call used, and the GlobalScope
ones hid that it was global.

source-local/src/main/kotlin/tachiyomi/source/local/LocalSource.kt

@@ -15,9 +15,11 @@ import eu.kanade.tachiyomi.source.model.SManga
 import eu.kanade.tachiyomi.source.model.SMangaUpdate
 import eu.kanade.tachiyomi.util.lang.compareToCaseInsensitiveNaturalOrder
 import kotlinx.coroutines.CancellationException
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.async
 import kotlinx.coroutines.awaitAll
 import kotlinx.coroutines.supervisorScope
+import kotlinx.coroutines.withContext
 import kotlinx.datetime.LocalDate
 import kotlinx.datetime.TimeZone
 import kotlinx.datetime.atStartOfDayIn
@@ -31,7 +33,6 @@ import nl.adaptivity.xmlutil.serialization.XML
 import tachiyomi.core.common.i18n.stringResource
 import tachiyomi.core.common.storage.extension
 import tachiyomi.core.common.storage.nameWithoutExtension
-import tachiyomi.core.common.util.lang.withIOContext
 import tachiyomi.core.common.util.system.ImageUtil
 import tachiyomi.core.common.util.system.logcat
 import tachiyomi.core.metadata.comicinfo.COMIC_INFO_FILE
@@ -86,7 +87,9 @@ class LocalSource(
 
     override suspend fun getLatestUpdates(page: Int) = getSearchManga(page, "", LatestFilters)
 
-    override suspend fun getSearchManga(page: Int, query: String, filters: FilterList): MangasPage = withIOContext {
+    override suspend fun getSearchManga(page: Int, query: String, filters: FilterList): MangasPage = withContext(
+        Dispatchers.IO,
+    ) {
         val lastModifiedLimit = if (filters === LatestFilters) {
             System.currentTimeMillis() - LATEST_THRESHOLD
         } else {
@@ -160,7 +163,7 @@ class LocalSource(
     }
 
     // Manga details related
-    private suspend fun getMangaDetails(manga: SManga): SManga = withIOContext {
+    private suspend fun getMangaDetails(manga: SManga): SManga = withContext(Dispatchers.IO) {
         coverManager.find(manga.url)?.let {
             manga.thumbnail_url = it.uri.toString()
         }
@@ -224,7 +227,7 @@ class LocalSource(
             logcat(LogPriority.ERROR, e) { "Error setting manga details from local metadata for ${manga.title}" }
         }
 
-        return@withIOContext manga
+        return@withContext manga
     }
 
     private fun <T> getComicInfoForChapter(chapter: UniFile, block: (InputStream) -> T): T? {
@@ -287,7 +290,7 @@ class LocalSource(
     }
 
     // Chapters
-    private suspend fun getChapterList(manga: SManga): List<SChapter> = withIOContext {
+    private suspend fun getChapterList(manga: SManga): List<SChapter> = withContext(Dispatchers.IO) {
         val chapters = fileSystem.getFilesInMangaDirectory(manga.url)
             // Only keep supported formats
             .filterNot { it.name.orEmpty().startsWith('.') }