Rename room crate to call

Also, rename `client::Call` to `client::IncomingCall`.

Co-Authored-By: Nathan Sobo <nathan@zed.dev>

crates/call/src/participant.rs

@@ -0,0 +1,31 @@
+use anyhow::{anyhow, Result};
+use client::proto;
+use gpui::ModelHandle;
+use project::Project;
+
+pub enum ParticipantLocation {
+    Project { project_id: u64 },
+    External,
+}
+
+impl ParticipantLocation {
+    pub fn from_proto(location: Option<proto::ParticipantLocation>) -> Result<Self> {
+        match location.and_then(|l| l.variant) {
+            Some(proto::participant_location::Variant::Project(project)) => Ok(Self::Project {
+                project_id: project.id,
+            }),
+            Some(proto::participant_location::Variant::External(_)) => Ok(Self::External),
+            None => Err(anyhow!("participant location was not provided")),
+        }
+    }
+}
+
+pub struct LocalParticipant {
+    pub projects: Vec<ModelHandle<Project>>,
+}
+
+pub struct RemoteParticipant {
+    pub user_id: u64,
+    pub projects: Vec<ModelHandle<Project>>,
+    pub location: ParticipantLocation,
+}