refactor: Support more than one naddr instead of one

This commit supports multiple naddrs for sending issues to and searching
for repositories by extracting the embedded relays, and appending to the
address file instead of overwriting its previous contents. A header has
also been added to the `nostr-address` file to clarify its purpose.

This enhancement accommodates maintainers who distribute issue tracking
across multiple repositories, preventing confusion if the primary
maintainer steps down. Now, issues and patches will reference all
relevant repositories, not just one.

Note that repositories won't automatically include all maintainers'
addresses unless explicitly specified. Maintainers may manage a
repository under a project-specific public key rather than individual
keys. Addresses are only added to issues and patches when explicitly
provided via the command or written to the address file. This prevents
unintended inclusions and ensures clarity.

Suggested-by: DanConwayDev <DanConwayDev@protonmail.com>
Signed-off-by: Awiteb <a@4rs.nl>

src/nostr_utils/traits.rs

@@ -20,6 +20,7 @@ use nostr::{
     key::PublicKey,
     nips::{
         nip01::Coordinate,
+        nip19::Nip19Coordinate,
         nip21::Nip21,
         nip34::{GitIssue, GitRepositoryAnnouncement},
     },
@@ -164,3 +165,26 @@ impl Token<'_> {
         }
     }
 }
+
+/// Utility functions for working with lists of NIP-19 coordinates
+#[easy_ext::ext(NaddrsUtils)]
+impl Vec<Nip19Coordinate> {
+    /// Converts these coordinate addresses to basic coordinates
+    pub fn into_coordinates(self) -> Vec<Coordinate> {
+        self.into_iter().map(|n| n.coordinate).collect()
+    }
+
+    /// Extracts all relay URLs from these coordinates
+    pub fn extract_relays(&self) -> Vec<RelayUrl> {
+        self.iter().flat_map(|n| n.relays.clone()).collect()
+    }
+}
+
+/// Utility functions for working with lists of repository announcement
+#[easy_ext::ext(ReposUtils)]
+impl Vec<GitRepositoryAnnouncement> {
+    /// Extracts all relay URLs from these reposotoies
+    pub fn extract_relays(&self) -> Vec<RelayUrl> {
+        self.iter().flat_map(|n| n.relays.clone()).collect()
+    }
+}