tests: Integrate old tests for filedatabase
These tests were implemented as code the FileDb command of a test device server.
This is non-standard and also unknown if we ever executed them.
So let's integrate them as old tests.
The code needed the following adaptations:
- Replace std::cout with our standard TEST_LOG macro
- As this is now client side code we have to use the tango client API instead of the server API
- Use the DeviceProxy API for reading/writing properties
In addition we also remove the now unused FileDb command.
Close #1173 (closed)