Previously, it was possible to search for specific math operations in link-drag-search but not in the normal add menu. This patch adds support for searching for specific operations in various math nodes. A good trick for adding e.g. a vector add node is to search for `vadd` (similarly with `iadd`). The menu itself looks unchanged. This patch only adds additional elements to the search. Pull Request: https://projects.blender.org/blender/blender/pulls/138534