Add regular query workflow templates from custom_nodes

[MakkiShizu]

Some additions and revise for #6193
I have noticed that many custom nodes do not strictly establish the example_workflows folder, and for the original code, of examples provided by only a small number custom nodes can be found. Therefore, I believe that some regular queries such as example and workflow should be added to search for these example workflows.
In my local simple test, It was able to work.

[asagi4]

Just as a note here that in prompt control specifically, I didn't move the other workflows to example_workflows yet because I want to clean them up first.

However, there probably exist quite a few repos that use "workflows" as the directory so looking into it is likely not a bad idea.

[MakkiShizu]

Implemented at #7836