Implement better error system and segregate errors and commands (#23)

* chore: Progress on amend_settings command

Signed-off-by: quexeky <git@quexeky.dev>

* chore(errors): Progress on better error handling with segragation of files

* chore: Progress on amend_settings command

Signed-off-by: quexeky <git@quexeky.dev>

* chore(commands): Separated commands under each subdirectory into respective commands.rs files

Signed-off-by: quexeky <git@quexeky.dev>

* chore(errors): Almost all errors and commands have been segregated

* chore(errors): Added drop server error

Signed-off-by: quexeky <git@quexeky.dev>

* feat(core): Update to using nightly compiler

Signed-off-by: quexeky <git@quexeky.dev>

* chore(errors): More progress on error handling

Signed-off-by: quexeky <git@quexeky.dev>

* chore(errors): Implementing Try and FromResidual for UserValue

Signed-off-by: quexeky <git@quexeky.dev>

* refactor(errors): Segregated errors and commands from code, and made commands return UserValue struct

Signed-off-by: quexeky <git@quexeky.dev>

* fix(errors): Added missing files

* chore(errors): Convert match statement to map_err

* feat(settings): Implemented settings editing from UI

* feat(errors): Clarified return values from retry_connect command

* chore(errors): Moved autostart commands to autostart.rs

* chore(process manager): Converted launch_process function for games to use game_id

---------

Signed-off-by: quexeky <git@quexeky.dev>

src-tauri/src/database/settings.rs

@@ -0,0 +1,24 @@
+use serde::{Deserialize, Serialize};
+
+#[derive(Serialize, Deserialize, Clone, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct Settings {
+    pub autostart: bool,
+    pub max_download_threads: usize,
+    // ... other settings ...
+}
+impl Default for Settings {
+    fn default() -> Self {
+        Self {
+            autostart: false,
+            max_download_threads: 4,
+        }
+    }
+}
+// Ideally use pointers instead of a macro to assign the settings
+// fn deserialize_into<T>(v: serde_json::Value, t: &mut T) -> Result<(), serde_json::Error>
+//     where T: for<'a> Deserialize<'a>
+// {
+//     *t = serde_json::from_value(v)?;
+//     Ok(())
+// }