Add buffer authority to upgradeable loader (bp #14482) (#14503)

* Add buffer authority to upgradeable loader (#14482)

(cherry picked from commit 58487c6360)

* resolve conflicts

* nudge

Co-authored-by: Jack May <jack@solana.com>

sdk/program/src/instruction.rs

@@ -180,6 +180,12 @@ pub enum InstructionError {
 
     #[error("Program failed to compile")]
     ProgramFailedToCompile,
+
+    #[error("Account is immutable")]
+    Immutable,
+
+    #[error("Incorrect authority provided")]
+    IncorrectAuthority,
 }
 
 #[derive(Debug, PartialEq, Clone, Serialize, Deserialize)]