rewrite funcs in line with bound considerations

Author: anihamde

pyth-sdk/src/error.rs

@@ -1,13 +1,15 @@
 use thiserror::Error;
 
 #[derive(Error, Debug, Copy, Clone, PartialEq)]
-pub enum LiquidityOracleError {
-    #[error("deposits exceeds max depositable")]
-    ExceedsMaxDeposits,
-    #[error("initial discount rate should not be greater than final discount rate")]
+pub enum OracleError {
+    #[error("initial endpoint should not be greater than or equal to final endpoint")]
+    InitialEndpointExceedsFinalEndpoint,
+    #[error("initial discount should not exceed final discount, for collateral valuation")]
     InitialDiscountExceedsFinalDiscount,
     #[error("final discount rate should not be greater than the discount precision")]
     FinalDiscountExceedsPrecision,
+    #[error("initial premium should not exceed final premium, for borrow valuation")]
+    InitialPremiumExceedsFinalPremium,
     #[error("None encountered")]
     NoneEncountered,
     #[error("i64 try from error")]