[FEATURE] Experiment with GPU calculations

[petersalemink95]

Description:

Currently, Power Grid Model performs all numerical calculations on the CPU. To better understand potential performance improvements, we propose a small proof-of-concept (PoC) to investigate whether GPU acceleration could be beneficial for selected workloads.

Goal of this PoC:

• Evaluate potential speedups of GPU-based computation compared to the existing CPU implementation

• Assess development complexity and maintenance impact

Scope (PoC):

• Implement a minimal GPU-accelerated version for power flow calculations

• Benchmark against the current CPU implementation using representative test cases

• Document findings, limitations, and recommendations

Note: the PoC might not be added to the project - however, findings will be documented here