Altium: Script to add all symbols to a schematic?
I'm not sure this would be a desirable feature because it would lead to a huge mess in most cases, and would be a very niche requirement. If you really want a script to do this, you might want to look into writing your own using Pascal, DelphiScript, EnableBasic, VB Script, or JavaScript. These are the languages Altium recognizes. You can find a guide on scripting at the following link:

https://techdocs.altium.com/display/SCRT/Scripting

I cannot seem to find an updated version, which suggests that the above page is still valid.