Added most node_info information

That I've found relevant or interesting at least

src/monero_rpc.rs

@@ -9,7 +9,7 @@ pub struct NodeInfo {
 
 #[derive(Serialize, Deserialize, Debug)]
 pub struct NodeInfoInner {
-    adjusted_time: u64,
+    pub adjusted_time: u64,
     alt_blocks_count: u64,
     block_size_limit: u64,
     block_size_median: u64,
@@ -20,10 +20,10 @@ pub struct NodeInfoInner {
     credits: u64,
     cumulative_difficulty: u64,
     cumulative_difficulty_top64: u64,
-    database_size: u64,
+    pub database_size: u64,
     difficulty: u64,
     difficulty_top64: u64,
-    free_space: u64,
+    pub free_space: u64,
     grey_peerlist_size: u64,
     height: u64,
     height_without_bootstrap: u64,
@@ -35,7 +35,7 @@ pub struct NodeInfoInner {
     restricted: bool,
     rpc_connections_count: u64,
     stagenet: bool,
-    start_time: u64,
+    pub start_time: u64,
     status: String,
     synchronized: bool,
     target: u64,
@@ -53,13 +53,13 @@ pub struct NodeInfoInner {
     wide_cumulative_difficulty: String,
     wide_difficulty: String,
     #[serde(skip_deserializing, default = "none")]
-    time_up_pretty: Option<String>,
+    pub time_up_pretty: String,
     #[serde(skip_deserializing, default = "none")]
-    space_left_pretty: Option<String>,
+    pub free_space_pretty: String,
     #[serde(skip_deserializing, default = "none")]
-    db_size_pretty: Option<String>,
+    pub db_size_pretty: String,
 }
 
-fn none() -> Option<String> {
-    None
+fn none() -> String {
+    "".to_string()
 }