fixed issue with whitespace in node parsing for replace_nodes

[raska-s]

I encountered an issue when converting STEP files to graphs in stepfiles where there is some whitespace after the key/node, example:

/utils.py", line 76, in replace_nodes
    node.parameters[i1] = fast_dict_search[par1]
                          ~~~~~~~~~~~~~~~~^^^^^^
KeyError: '#1149    '

This fixes the issue by stripping the whitespace.

Please consider integrating this fix into the main branch.

Thanks,
Raska S