[Pass] Add keepdims convert pass for OpenCL

[zhaoyang-star]

KeepdimsConvertPass splits some ops whose attribute keepdims or keep_dim is false to two ops.
The reason for adding this pass is that it is hard for gpu to do reshape opterations in arg_max/reduce_mean, etc,. So we split this problem.

 * For example:
 *        |
 *       var1
 *        v
 *   OP: arg_max(keepdims=false)
 *        |
 *       var2
 *        v
 *
 * After this pass is applied:
 *        |
 *       var1
 *        v
 *   OP: arg_max(keepdims=true)
 *        |
 *    var2/trans
 *        v
 *   OP: reshape(shape = original arg_max's output dims)
 *        |
 *       var2
 *        v
 * 

原始模型部分截图：

应用本 Pass 后：

已在 text_intention_v1 模型中验证精度正确。

[paddle-bot-old]

Thanks for your contribution!

[daming5432]

LGTM

[zhenlin-work]

LGTM