Refactor `mullvad-relay-selector`

Implement a system built on 'queries' for selecting appropriate relays.
A query is a set of constraints which dictates which relay(s) that *can*
be chosen by the relay selector.

The user's settings can naturally be expressed as a query. The semantics
of merging two queries in a way that always prefer user settings is
defined by the new `Intersection` trait.

Split `mullvad-relay-selector` into several modules:

- `query.rs`: Definition of a query on different types of relays. This
module is integral to the new API of `mullvad-relay-selector`
- `matcher.rs`: Logic for filtering out candidate relays based on a
query.
- `detailer.rs`: Logic for deriving connection details for the selected
relay.
- `tests/`: Integration tests for the new relay selector. These tests
only use the public APIs of `RelaySelector` and make sure that the
output matches the expected output in different scenarios.

1 files changed, 4 insertions, 1 deletions

diff --git a/mullvad-cli/src/cmds/debug.rs b/mullvad-cli/src/cmds/debug.rs
index 832e6eaa8e..d67194b058 100644
--- a/mullvad-cli/src/cmds/debug.rs
+++ b/mullvad-cli/src/cmds/debug.rs
@@ -1,6 +1,9 @@
 use anyhow::Result;
 use mullvad_management_interface::MullvadProxyClient;
-use mullvad_types::relay_constraints::{Constraint, RelayConstraints, RelaySettings};
+use mullvad_types::{
+    constraints::Constraint,
+    relay_constraints::{RelayConstraints, RelaySettings},
+};
 
 #[derive(clap::Subcommand, Debug)]
 pub enum DebugCommands {