Add a possibility to work with RLocalCachedMap reactively

[WildWind03]

Is your feature request related to a problem? Please describe.
In highload systems, it may be too expensive to make requests to Redis too often. Using a not reactive approach, it's possible to enable local caching and use RLocalCachedMap to reduce amount of requests to Redis. However, in a reactive system, currenty it's not an option.
Describe the solution you'd like
I think it would be very nice to be able to use RLocalCachedMap reactively.
Describe alternatives you've considered
As an alternative, I have to implement a custom caching logic to reduce amount of requests to Redis.

[mrniko]

Done