Add Time Coordinator Integrationtests

[KonradBreitsprecherBkd]

Goal

Enable deterministic, runtime step-size adjustments in coordinated simulation so the new integration tests in SilKit/IntegrationTests/ITest_TimeCoordinator.cpp pass:

• test_fixed_schedule_slowdown_by_time_coordinator
• test_fixed_schedule_slowdown_by_participant

Functional Requirements

1. Runtime step-size change API

• Provide an API on time synchronization service to request a new simulation step size at runtime (as referenced in tests):
  • SetStepSize(std::chrono::nanoseconds)
• The API must be callable from within a simulation step handler.

2. Global schedule effect

• A step-size change requested by one coordinated participant must affect the global coordinated schedule (not only the caller).
• This must work for:
  • a dedicated coordinator participant (TimeCoordinator), and
  • a regular participant (Publisher).

3. Fixed slowdown sequence support

For the cycle around 10ms, the following requested sequence must be supported:

1. At 10ms, set step size to 1us
2. At 10ms + 1us, set step size to 999us
3. At 11ms, set step size back to 1ms

The resulting simulation-step timestamps for all coordinated participants must include:

• 0ms, 1ms, 2ms, ..., 10ms, 10ms+1us, 11ms, 12ms

4. Pub/Sub timing expectation

• A message published at simulation time 10ms must be received and visible by 10ms+1us.
• The tests validate this via subscriber bookkeeping in its simulation step handler.

Determinism / Consistency Requirements

• All coordinated participants must observe the same global step timeline for the slowdown window.
• No participant may skip the inserted 10ms+1us step when slowdown is active.

Compatibility Requirements

• Existing coordinated simulations without SetStepSize(...) calls must preserve current behavior.