fix(model-server): do not put objects into store in request thread

This is already done in `putRepositoryObjects`.
In `postRepositoryBranch` this should also be done.

It was not a critical issue because the model client only sent at most 1000 objects to `postRepositoryBranch`.
Still, if something blocking happened in Ignite, it might have blocked the request thread.

Author: Oleksandr Dzhychko

model-server/src/main/kotlin/org/modelix/model/server/handlers/ModelReplicationServer.kt

@@ -216,8 +216,11 @@ class ModelReplicationServer(
         val branchRef = repositoryId(repository).getBranchReference(branch)
         val deltaFromClient = call.receive<VersionDelta>()
         deltaFromClient.checkObjectHashes()
-        @OptIn(RequiresTransaction::class) // no transactions required for immutable store
-        repositoriesManager.getStoreClient(RepositoryId(repository), true).putAll(deltaFromClient.getAllObjects())
+        val objectsFromClient = deltaFromClient.getAllObjects()
+        withContext(Dispatchers.IO) {
+            @OptIn(RequiresTransaction::class) // no transactions required for immutable store
+            repositoriesManager.getStoreClient(RepositoryId(repository), true).putAll(objectsFromClient)
+        }
         @OptIn(RequiresTransaction::class)
         val mergedHash = runWrite {
             repositoriesManager.mergeChanges(branchRef, deltaFromClient.versionHash)