[REFACTOR] Introduce QNX Single Thread Logging

[minminlittleshrimp]

1. Pthread APIs in QNX follow POSIX standard, hence, to avoid undefined behaviors:

• Return value from each API call will be handled
• Manually allocate stack size for thread
• Reduce thread queue to one for logging only to avoid unlimited threads creation
• Use only 1 thread to handle logging, with stack size fixed to 12K (4K aligned)

2. Injection callback:

• Since only 1 thread is used, callback injection will now do infinity wait inside slogger2_callback

3. Handle properly dlt thread in normal exit:

• Add an atomic_bool for thread cancellation in normal main thread exit case.

4. Handle slog2_thread heap memory:

• slog2_thread is now allocated on HEAP, in case of failure or normal exit, free this HEAP allocated memory is required to prevent memory leak. During thread allocation on heap, the pointer stackaddr shall be round up to the nearest aligned memory address within 16K memory allocated.

Example: Heap 16K memory
|-------------|------------------------|
0x1003 0x2000-aligned MAX_MEM

MAX_MEM - 0x1003 = 16K
MAX_MEM - 0x2000 >= 12K