fetch contact lists

If we don't have a contact list, make sure to fetch one

Signed-off-by: William Casarin <jb55@jb55.com>

src/subscriptions.rs

@@ -0,0 +1,23 @@
+use std::collections::HashMap;
+
+pub enum SubKind {
+    /// Initial subscription. This is the first time we do a remote subscription
+    /// for a timeline
+    Initial,
+
+    /// One shot requests, we can just close after we receive EOSE
+    OneShot,
+
+    /// We are fetching a contact list so that we can use it for our follows
+    /// Filter.
+    // TODO: generalize this to any list?
+    FetchingContactList(u32),
+}
+
+/// Subscriptions that need to be tracked at various stages. Sometimes we
+/// need to do A, then B, then C. Tracking requests at various stages by
+/// mapping uuid subids to explicit states happens here.
+#[derive(Default)]
+pub struct Subscriptions {
+    pub subs: HashMap<String, SubKind>,
+}