voyager docs & vm cleanup (#3070)

- removed types on `VoyagerMessage` and `Call`/`Data`/`Callback`
- due to this change, i have removed `frunk` and all of the type level
hackery in `voyager-vm`. we have strayed too far from the light of god
for this to be useful anymore
- added docs to `voyager-vm`
- added more docs to `voyager`
- renamed variables of type `Op` named `msg` to `op` across the repo for
consistency
- implemented parent id tracking in `pg-queue`
- removed the pre-enqueue pass in favor of a "filter"
(`pre_reenqueue_passes: &'a O` -> `filter: &'a T::Filter`), this
massively improved performance of the filtering
- `/msg` -> `/enqueue`
  - removed `/msgs` bc i don't think i ever even used it
- cleaned up `voyager-vm` a bit, mainly splitting the massive lib.rs
into modules
- clean up voyager cli and add some more useful commands
  - remove `voy-send-msg` as the cli now has a command for this