Add more replacement suspend functions for source APIs

These are basically 1-to-1 replacements for the existing RxJava APIs.
This will make the initial migration off of RxJava simpler. We'll
revisit the actual call flows in followup versions of the API.

(cherry picked from commit 26c5d761da4ba577481f41e63f03952b8a6c323f)

# Conflicts:
#	data/src/main/java/tachiyomi/data/source/SourcePagingSource.kt
#	source-api/src/commonMain/kotlin/eu/kanade/tachiyomi/source/online/HttpSource.kt
#	source-api/src/commonMain/kotlin/eu/kanade/tachiyomi/source/online/HttpSourceFetcher.kt

app/src/main/java/exh/md/handlers/BilibiliHandler.kt

@@ -1,7 +1,6 @@
 package exh.md.handlers
 
 import eu.kanade.tachiyomi.network.POST
-import eu.kanade.tachiyomi.network.asObservableSuccess
 import eu.kanade.tachiyomi.network.awaitSuccess
 import eu.kanade.tachiyomi.network.interceptor.rateLimit
 import eu.kanade.tachiyomi.network.parseAs
@@ -22,6 +21,7 @@ import okhttp3.Request
 import okhttp3.RequestBody.Companion.toRequestBody
 import okhttp3.Response
 import rx.Observable
+import tachiyomi.core.util.lang.runAsObservable
 import uy.kohesive.injekt.injectLazy
 import java.util.concurrent.TimeUnit
 
@@ -154,12 +154,13 @@ class BilibiliHandler(currentClient: OkHttpClient) {
             .mapIndexed { i, page -> Page(i, page.path, "") }
     }
 
+    suspend fun getImageUrl(page: Page): String {
+        val response = client.newCall(imageUrlRequest(page)).awaitSuccess()
+        return imageUrlParse(response)
+    }
+
     fun fetchImageUrl(page: Page): Observable<String> {
-        return client.newCall(imageUrlRequest(page))
-            .asObservableSuccess()
-            .map {
-                imageUrlParse(it)
-            }
+        return runAsObservable { getImageUrl(page) }
     }
 
     private fun imageUrlRequest(page: Page): Request {

app/src/main/java/exh/md/handlers/PageHandler.kt

@@ -134,4 +134,13 @@ class PageHandler(
             else -> superMethod(page)
         }
     }
+
+    suspend fun getImageUrl(page: Page, superMethod: suspend (Page) -> String): String {
+        return when {
+            page.url.contains("/bfs/comic/") -> {
+                bilibiliHandler.getImageUrl(page)
+            }
+            else -> superMethod(page)
+        }
+    }
 }

app/src/main/java/exh/util/DataSaver.kt

@@ -8,7 +8,6 @@ import eu.kanade.tachiyomi.source.Source
 import eu.kanade.tachiyomi.source.model.Page
 import eu.kanade.tachiyomi.source.online.HttpSource
 import okhttp3.Response
-import rx.Observable
 import tachiyomi.core.preference.Preference
 
 interface DataSaver {
@@ -22,15 +21,6 @@ interface DataSaver {
             }
         }
 
-        fun HttpSource.fetchImage(page: Page, dataSaver: DataSaver): Observable<Response> {
-            val imageUrl = page.imageUrl ?: return fetchImage(page)
-            page.imageUrl = dataSaver.compress(imageUrl)
-            return fetchImage(page)
-                .doOnNext {
-                    page.imageUrl = imageUrl
-                }
-        }
-
         suspend fun HttpSource.getImage(page: Page, dataSaver: DataSaver): Response {
             val imageUrl = page.imageUrl ?: return getImage(page)
             page.imageUrl = dataSaver.compress(imageUrl)

app/src/main/java/exh/util/SearchOverride.kt

@@ -35,3 +35,29 @@ fun UrlImportableSource.urlImportFetchSearchManga(context: Context, query: Strin
         }
         else -> fail()
     }
+
+
+/**
+ * A version of fetchSearchManga that supports URL importing
+ */
+suspend fun UrlImportableSource.urlImportFetchSearchMangaSuspend(context: Context, query: String, fail: suspend () -> MangasPage): MangasPage =
+    when {
+        query.startsWith("http://") || query.startsWith("https://") -> {
+            val res = galleryAdder.addGallery(
+                context = context,
+                url = query,
+                fav = false,
+                forceSource = this
+            )
+
+            MangasPage(
+                if (res is GalleryAddEvent.Success) {
+                    listOf(res.manga.toSManga())
+                } else {
+                    emptyList()
+                },
+                false,
+            )
+        }
+        else -> fail()
+    }