Add SPL Token-specific rpc endpoints (#11231)

* Simplify account-decoder program ids + spl_token helper

* Spl program namespace version

* Add getTokenAccountBalance endpoint

* Remove token program id from getTokenAccountBalance request

* Add getTokenSupply endpoint

* Remove token program id from getTokenSupply request

* Add getTokenAccountsByOwner/Delegate endpoints

* Remove token program id from getTokenAccountsByOwner/Delegate requests

* Named parameter

client/src/rpc_config.rs

@@ -58,3 +58,10 @@ pub struct RpcProgramAccountsConfig {
     #[serde(flatten)]
     pub account_config: RpcAccountInfoConfig,
 }
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub enum RpcTokenAccountsFilter {
+    Mint(String),
+    ProgramId(String),
+}