CLI: Support querying FeeCalculator for a specific blockhash (bp #15555) (#15577)

* cli-output: Minor refactor of CliFees

(cherry picked from commit ebd56f7ff4)

* CLI: Support querying fees by blockhash

(cherry picked from commit 21e08b5b2c)

Co-authored-by: Trent Nelson <trent@solana.com>

cli-output/src/cli_output.rs

@@ -1406,17 +1406,17 @@ impl fmt::Display for CliSupply {
 
 #[derive(Serialize, Deserialize)]
 #[serde(rename_all = "camelCase")]
-pub struct CliFees {
+pub struct CliFeesInner {
     pub slot: Slot,
     pub blockhash: String,
     pub lamports_per_signature: u64,
-    pub last_valid_slot: Slot,
+    pub last_valid_slot: Option<Slot>,
 }
 
-impl QuietDisplay for CliFees {}
-impl VerboseDisplay for CliFees {}
+impl QuietDisplay for CliFeesInner {}
+impl VerboseDisplay for CliFeesInner {}
 
-impl fmt::Display for CliFees {
+impl fmt::Display for CliFeesInner {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         writeln_name_value(f, "Blockhash:", &self.blockhash)?;
         writeln_name_value(
@@ -1424,8 +1424,51 @@ impl fmt::Display for CliFees {
             "Lamports per signature:",
             &self.lamports_per_signature.to_string(),
         )?;
-        writeln_name_value(f, "Last valid slot:", &self.last_valid_slot.to_string())?;
-        Ok(())
+        let last_valid_slot = self
+            .last_valid_slot
+            .map(|s| s.to_string())
+            .unwrap_or_default();
+        writeln_name_value(f, "Last valid slot:", &last_valid_slot)
+    }
+}
+
+#[derive(Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct CliFees {
+    #[serde(flatten, skip_serializing_if = "Option::is_none")]
+    pub inner: Option<CliFeesInner>,
+}
+
+impl QuietDisplay for CliFees {}
+impl VerboseDisplay for CliFees {}
+
+impl fmt::Display for CliFees {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        match self.inner.as_ref() {
+            Some(inner) => write!(f, "{}", inner),
+            None => write!(f, "Fees unavailable"),
+        }
+    }
+}
+
+impl CliFees {
+    pub fn some(
+        slot: Slot,
+        blockhash: Hash,
+        lamports_per_signature: u64,
+        last_valid_slot: Option<Slot>,
+    ) -> Self {
+        Self {
+            inner: Some(CliFeesInner {
+                slot,
+                blockhash: blockhash.to_string(),
+                lamports_per_signature,
+                last_valid_slot,
+            }),
+        }
+    }
+    pub fn none() -> Self {
+        Self { inner: None }
     }
 }