feat: Allows to create sessions in sessions service (#384)

Protos/V1/sessions_common.proto

@@ -105,3 +105,20 @@ message CancelSessionRequest {
 message CancelSessionResponse {
   SessionRaw session = 1; /** The session. */
 }
+
+/**
+ * Request for creating session.
+ */
+message CreateSessionRequest {
+  TaskOptions default_task_option = 1; /** Default tasks options for tasks in the session */
+  repeated string partition_ids = 2; /** List of partitions allowed during the session */
+}
+
+/*
+	Reply after session creation.
+	We have this reply in case of success.
+	When the session creation is not successful, there is an rpc exception.
+*/
+message CreateSessionReply {
+  string session_id = 1; /** Session id of the created session if successful */
+}

Protos/V1/sessions_service.proto

@@ -27,4 +27,9 @@ service Sessions {
    * Cancel a session by its id.
    */
   rpc CancelSession(CancelSessionRequest) returns (CancelSessionResponse) {}
+
+  /**
+   * Create a session
+   */
+  rpc CreateSession(CreateSessionRequest) returns (CreateSessionReply);
 }