Decode native-program and sysvar accounts (#11463)

* Pass pubkey in to account-decoder for sysvars

* Decode sysvar accounts

* Decode config accounts; move validator-info lower

* Decode stake accounts

* Review comments

* Stringify any account lamports and epochs that can be set to u64::MAX

account-decoder/src/validator_info.rs

@@ -0,0 +1,18 @@
+use solana_config_program::ConfigState;
+
+pub const MAX_SHORT_FIELD_LENGTH: usize = 70;
+pub const MAX_LONG_FIELD_LENGTH: usize = 300;
+pub const MAX_VALIDATOR_INFO: u64 = 576;
+
+solana_sdk::declare_id!("Va1idator1nfo111111111111111111111111111111");
+
+#[derive(Debug, Deserialize, PartialEq, Serialize, Default)]
+pub struct ValidatorInfo {
+    pub info: String,
+}
+
+impl ConfigState for ValidatorInfo {
+    fn max_space() -> u64 {
+        MAX_VALIDATOR_INFO
+    }
+}