Separate discovery from recovery contact information

**Is your feature request related to a problem? Please describe.**
I would like to be discoverable via my phone number and work email but I don't want to use them as recovery options. Right now, I need to first add contact information for recovery before I can use them for discovery.

**Describe the solution you'd like**
I want to set an email or phone number for discovery without using it for recovery.

**Describe alternatives you've considered**
None

The issue names no files, tests, or entry points. Start by mapping how Element clients currently handle contact information for discovery and recovery, then define and verify separate settings so an email or phone number can be discoverable without being a recovery option.

Written by the indexing model from the issue text.