Half-written metadata

[kirillt]

We need atomic writing for metadata and other computed values.

• Write files atomically arklib#48

kotlinx.serialization.json.internal.JsonDecodingException: Cannot begin reading element, unexpected token: 10 at path: $
JSON input: 
	at kotlinx.serialization.json.internal.JsonExceptionsKt.JsonDecodingException(JsonExceptions.kt:24)
	at kotlinx.serialization.json.internal.JsonExceptionsKt.JsonDecodingException(JsonExceptions.kt:32)
	at kotlinx.serialization.json.internal.AbstractJsonLexer.fail(AbstractJsonLexer.kt:528)
	at kotlinx.serialization.json.internal.AbstractJsonLexer.fail$default(AbstractJsonLexer.kt:526)
	at kotlinx.serialization.json.internal.JsonTreeReader.read(JsonTreeReader.kt:104)
	at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeJsonElement(StreamingJsonDecoder.kt:33)
	at kotlinx.serialization.json.JsonElementSerializer.deserialize(JsonElementSerializers.kt:51)
	at kotlinx.serialization.json.JsonElementSerializer.deserialize(JsonElementSerializers.kt:27)
	at kotlinx.serialization.json.internal.PolymorphicKt.decodeSerializableValuePolymorphic(Polymorphic.kt:59)
	at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableValue(StreamingJsonDecoder.kt:38)
	at kotlinx.serialization.json.Json.decodeFromString(Json.kt:100)
	at kotlinx.serialization.json.Json.parseToJsonElement(Json.kt:128)
	at space.taran.arklib.domain.meta.MetadataStorage.valueFromBinary(MetadataStorage.kt:35)
	at space.taran.arklib.domain.storage.FolderStorage$readFromDisk$jobs$2$1.invokeSuspend(FolderStorage.kt:94)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:106)
	at kotlinx.coroutines.internal.LimitedDispatcher.run(LimitedDispatcher.kt:42)
	at kotlinx.coroutines.scheduling.TaskImpl.run(Tasks.kt:95)
	at kotlinx.coroutines.scheduling.CoroutineScheduler.runSafely(CoroutineScheduler.kt:570)
	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.executeTask(CoroutineScheduler.kt:750)
	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.runWorker(CoroutineScheduler.kt:677)
	at kotlinx.coroutines.scheduling.CoroutineScheduler$Worker.run(CoroutineScheduler.kt:664)
	Suppressed: kotlinx.coroutines.DiagnosticCoroutineContextException: [StandaloneCoroutine{Cancelling}@8ef4f0d, Dispatchers.IO]