Adapted to switch in notation of stress in IO functions and calculator

• updated read_thermo function in io.py
  • added cases with 12 (orthorhombic) and 18 columns (triclinic)
  • replaced Lx... with cell_xx... and Px... with stress_xx... throughout
  • updated tests
• updated Docker image to GPUMD 3.3.1
• updated ASE calculator
  • added support for full stress tensor
  • updated tests

Closes #18 (closed)