rustyphoenixclockbackend

This is the Rust version of https://gitlab.in2p3.fr/CTA-LAPP/PHOENIX_LIBS2/PhoenixClock project. This project aims to ease the use of clock in complex environments, especially distributed environments where latencies measurement has to be precise and reproductible when running unit tests. **PhoenixClock** provide **PGenericClock**, a template classe which takes two arguments : - The main clock backend (could be **clock**, **PClockNs** for nanoseconds, etc) - A mock of a clock, **PClockMock**, which can play, register and replay a sequence of clock calls These clocks are activated with a mode `PClockMode::PClockMode` which can be : - `PClockMode::NO_MOCK` : for a normal usage - `PClockMode::MOCK` : when the mock the desired clock is played - `PClockMode::MOCK_RECORD` : when the real clock backend is used but the clock mock is recording (could be usefull for debugging or to desing new unit tests quickly)