The previous approach was a bit messy with the db access and could have potential race conditions and data inconsistency
Also replaces format for f-functions for readability
- The appointment constructions is left in Watchtower (via on_commit_revocation method)
- The tower interaction is moved to net/http so it can be reused
- Adds missing logic for invalid resposes by the tower (e.g invalid signatures)
- Logs data identified by tower_id instead of endpoint
- Adds Retrier to deal with retries (for connection errors and rejects) and moves sending logic to net/http
- Adds pending appointments to TowerInfo and serves that information via `get_tower_info` and `list_towers`
- Deals with connection errors (but not with rejections yet)
- Moves from *args to required params after 5f33d63cb6
- tower.endpoint -> tower.netaddr
- Adds basic exception handling logic in add_appointemnt
- Stores appointment data in the database (locator: signature) and keeps summary on memory
- Start and end time have to be dealt with (changes required on the tower side)
- Sends appointments to every register tower. We may want to manage this better
