Remove rxjava from API calls used by AccountViewModel::changeRelationship() (#3008)

* Remove rxjava from API calls used by AccountListFragment

* Remove rxjava from API calls used by AccountViewModel::changeRelationship()

The affected API functions are also called from

- ReportViewModel.kt
- SearchViewModel.kt
- AccountListFragment.kt
- SFragment.java
- TimelineCases.kt

so they have also been updated.

This change requires bridging from Java code to Kotlin `suspend` functions,
by creating wrappers for the `mute` and `block` functions that can be
called from Java and create a coroutine scope.

I've deliberately made this fairly ugly so that it sticks out and can be
removed later.

* Use "Throwable" type and name

* Delete 46.json

Not sure where this came from.

* Emit log messages with the correct tag

* Add another log tag, and lint

* Move viewModelScope.launch in to changeRelationshop()

app/src/main/java/com/keylesspalace/tusky/network/MastodonApi.kt

@@ -359,39 +359,39 @@ interface MastodonApi {
 
     @FormUrlEncoded
     @POST("api/v1/accounts/{id}/follow")
-    fun followAccount(
+    suspend fun followAccount(
         @Path("id") accountId: String,
         @Field("reblogs") showReblogs: Boolean? = null,
         @Field("notify") notify: Boolean? = null
-    ): Single<Relationship>
+    ): Relationship
 
     @POST("api/v1/accounts/{id}/unfollow")
-    fun unfollowAccount(
+    suspend fun unfollowAccount(
         @Path("id") accountId: String
-    ): Single<Relationship>
+    ): Relationship
 
     @POST("api/v1/accounts/{id}/block")
-    fun blockAccount(
+    suspend fun blockAccount(
         @Path("id") accountId: String
-    ): Single<Relationship>
+    ): Relationship
 
     @POST("api/v1/accounts/{id}/unblock")
-    fun unblockAccount(
+    suspend fun unblockAccount(
         @Path("id") accountId: String
-    ): Single<Relationship>
+    ): Relationship
 
     @FormUrlEncoded
     @POST("api/v1/accounts/{id}/mute")
-    fun muteAccount(
+    suspend fun muteAccount(
         @Path("id") accountId: String,
         @Field("notifications") notifications: Boolean? = null,
         @Field("duration") duration: Int? = null
-    ): Single<Relationship>
+    ): Relationship
 
     @POST("api/v1/accounts/{id}/unmute")
-    fun unmuteAccount(
+    suspend fun unmuteAccount(
         @Path("id") accountId: String
-    ): Single<Relationship>
+    ): Relationship
 
     @GET("api/v1/accounts/relationships")
     fun relationships(
@@ -399,14 +399,14 @@ interface MastodonApi {
     ): Single<List<Relationship>>
 
     @POST("api/v1/pleroma/accounts/{id}/subscribe")
-    fun subscribeAccount(
+    suspend fun subscribeAccount(
         @Path("id") accountId: String
-    ): Single<Relationship>
+    ): Relationship
 
     @POST("api/v1/pleroma/accounts/{id}/unsubscribe")
-    fun unsubscribeAccount(
+    suspend fun unsubscribeAccount(
         @Path("id") accountId: String
-    ): Single<Relationship>
+    ): Relationship
 
     @GET("api/v1/blocks")
     suspend fun blocks(