[PERF] use arraypool for visitor method params

Instead of creating a new array per visited node, use .NET's built-in System.Buffers.ArrayPool.
At the start of the node visit, rent an array from the pool that matches parametersCount.
Copy the parameters into it.
Pass it to the visitor.
Immediately after the visitor returns, return the array to the pool.

Search the visitor implementation for where method-parameter arrays are created and where parametersCount is available. Start by tracing the node-visit path, then verify that parameters are copied into a rented ArrayPool array, passed to the visitor, and returned immediately after the visitor returns.

Written by the indexing model from the issue text.