[BUG] picker GetInternalSignal index缓存问题

[miceforrat]

Description

picker getInternalSignal index 错误：
使用picker支持的所有语言调用getInternalSignal(String name, int index, boolean isArray)接口时，指定isArray=false且index >= 0，按道理来说应该根据index取出不同的值，但实测后续取到的XData数值完全一样，观察发现是template中相关逻辑有问题，应当使用name@index作为这种情况下的键去缓存XData

Steps to Reproduce

找一个内部信号存在数组的案例，比如fifo，编译时指定--rw 1，然后在python/java等语言中用循环设置不同的index调用GetInternalSignal。

Expected Result

上述应该取出不同偏移的值

Actual Result

但实际上上述XData指向的内容是一致的（用C++更明显）

Environment

• OS: Ubuntu24.04

Checklist

• I have searched the existing issues
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• I have reproduced the issue with the latest version
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[yaozhicheng]

@FrankOu2001