System info and memory measurement are not accurate on certain Apple devices

## Symptoms
### System info detection
On a M4 Max with 48GB running macOS 15.5 (Build 24F69), it detects such information

```
XPUInfo detected 1 devices
XPUInfo[Index=0, LUID=0x100000476]:
Name: Apple M2 Max
Driver Version: 15.0.0.0
Type: GPU, Integrated
Memory (MB): Dedicated = 0, Shared = 73728
APIs: Metal, Deserialized

CPU: Apple M2 Max
Cores: 12 (Hybrid)
Logical: 12

System Memory:
Installed Physical Memory (GB): 96
Total Physical Memory (GB): 96
Available Physical Memory At Init (GB): 1.7671
Page Size (KB): 16
System Information:
Manufacturer: Apple
Model: Mac14,13
TotalPhysicalMemory (GB): 96
OS: macOS Version 15.0 (Build 24A331), Build 15.0.0 (Build 24A331)
Uptime (Days): 29
```

Testing on other devices is in progress.

### Unclear meaning of GPU memory
Reported GPU memory usage has unclear meaning for hardware on Apple Silicon which has unified memory. More useful abstraction might be needed for such cases.

## Preliminary investigation
1. Device Name: "Apple M2 Max" instead of "Apple M4 Max"
This misinformation seems from
https://github.com/intel/LibXPUInfo/blob/e85d1f21d7d80ab355d5e8c44e3c9f69fd5e982a/LibXPUInfo_Metal.mm#L203

2. Memory Issues: 48GB system shows as 96GB total, 73728MB shared
seems from
https://github.com/intel/LibXPUInfo/blob/e85d1f21d7d80ab355d5e8c44e3c9f69fd5e982a/LibXPUInfo_Metal.mm#L148

3. OS Version: macOS 15.0 instead of 15.5
seems from
https://github.com/intel/LibXPUInfo/blob/e85d1f21d7d80ab355d5e8c44e3c9f69fd5e982a/LibXPUInfo_Metal.mm#L139
and
https://github.com/intel/LibXPUInfo/blob/e85d1f21d7d80ab355d5e8c44e3c9f69fd5e982a/LibXPUInfo_Metal.mm#L189

4. GPU memory measurement
For each device in the detected device vector, LibXPUInfo measures a memory budget struct like this
https://github.com/intel/LibXPUInfo/blob/e85d1f21d7d80ab355d5e8c44e3c9f69fd5e982a/LibXPUInfo.h#L186-L192
It's implementation for Metal device is as
https://github.com/intel/LibXPUInfo/blob/e85d1f21d7d80ab355d5e8c44e3c9f69fd5e982a/LibXPUInfo_Metal.mm#L86-L128
We may want to align on how to repurpose this per-device measurement for it to convey more meaningful info (such as memory access patterns), and then clarify on the correct implementation for it.