Support remaining Map Operations

[TamaraGunkel]

The ObjectReader can detect operation on Java maps. This is useful because process variables can be passed in map to a process e.g. when a process is started via the runtimeService.

Currently, the operations put and remove are supported as well as putValue from the Camunda map. To enhance the discovery of process variables, the remaining operations like putAll or putIfAbsent could be supported.