cli: add emoji picker to `rad issue react`

The help shows that `--emoji` is optional, however it was not.
Instead of making `--emoji` mandatory, I added an emoji picker
for the emojis featured in the web ui.

`--emoji` is now (really) optional, but can be used to react
with other emojis not included in the selector or the web ui.

radicle-cli/src/commands/issue.rs

@@ -137,7 +137,7 @@ pub enum Operation {
     },
     React {
         id: Rev,
-        reaction: Reaction,
+        reaction: Option<Reaction>,
         comment_id: Option<thread::CommentId>,
     },
     Assign {
@@ -435,7 +435,7 @@ impl Args for Options {
             },
             OperationName::React => Operation::React {
                 id: id.ok_or_else(|| anyhow!("an issue must be provided"))?,
-                reaction: reaction.ok_or_else(|| anyhow!("a reaction emoji must be provided"))?,
+                reaction,
                 comment_id,
             },
             OperationName::Delete => Operation::Delete {
@@ -595,6 +595,11 @@ pub fn run(options: Options, ctx: impl term::Context) -> anyhow::Result<()> {
                     Some(cid) => cid,
                     None => *term::io::comment_select(&issue).map(|(cid, _)| cid)?,
                 };
+                let reaction = match reaction {
+                    Some(reaction) => reaction,
+                    None => term::io::reaction_select()?,
+                };
+                // SAFETY: reaction is never None here.
                 issue.react(comment_id, reaction, true, &signer)?;
             }
         }

radicle-cli/src/terminal/io.rs

@@ -1,6 +1,7 @@
 use anyhow::anyhow;
 use radicle::cob::issue::Issue;
 use radicle::cob::thread::{Comment, CommentId};
+use radicle::cob::Reaction;
 use radicle::crypto::ssh::keystore::MemorySigner;
 use radicle::crypto::{ssh::Keystore, Signer};
 use radicle::profile::env::RAD_PASSPHRASE;
@@ -79,3 +80,13 @@ pub fn comment_select(issue: &Issue) -> anyhow::Result<(&CommentId, &Comment)> {
         .copied()
         .ok_or(anyhow!("failed to perform comment selection"))
 }
+
+pub fn reaction_select() -> anyhow::Result<Reaction> {
+    let emoji = Select::new(
+        "With which emoji do you want to react?",
+        vec!['🐙', '👾', '💯', '✨', '🙇', '🙅', '❤'],
+    )
+    .with_render_config(*CONFIG)
+    .prompt()?;
+    Ok(Reaction::new(emoji)?)
+}