Is there a Tool to List all Dynamics CRM plugins Including Hidden Ones?

you can use xrmtoolbox and it's plugin sql4cds or fetchxml builder and query sdkmessage and it's related table. It will give you all the info about your plugins.

few articles for refernce

How to get all crm steps names and messages from sql db

https://community.dynamics.com/crm/b/magnetismsolutionscrmblog/posts/quick-tip-locate-plugins-and-steps