As of today, all of these are able to be connected to on port 9999; I've not actually connected to all of them and verified they're on latest core or something like that; but their addresses my core knows about, and are able to be trivially connected to
## Issue being fixed or feature implemented
We did not previously ship any onion seeds. This results in people
needing to use `addnode` in order to actually get connected
## What was done?
Modified seed creation process to handle a list of onion seeds.
## How Has This Been Tested?
Running with and without onlynet=onion and with dnsseed=0 and deleting
peers.dat
## Breaking Changes
None
## Checklist:
- [x] I have performed a self-review of my own code
- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have added or updated relevant unit/integration/functional/e2e
tests
- [ ] I have made corresponding changes to the documentation
- [x] I have assigned this pull request to a milestone _(for repository
code-owners and collaborators only)_
