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/games/downloads/commands.rs

@@ -0,0 +1,31 @@
+use std::sync::{mpsc::SendError, Arc, Mutex};
+
+use crate::{
+    download_manager::{download_manager::DownloadManagerSignal, downloadable::Downloadable},
+    error::user_error::UserValue,
+    AppState,
+};
+
+use super::download_agent::GameDownloadAgent;
+
+#[tauri::command]
+pub fn download_game(
+    game_id: String,
+    game_version: String,
+    install_dir: usize,
+    state: tauri::State<'_, Mutex<AppState>>,
+) -> UserValue<(), SendError<DownloadManagerSignal>> {
+    let sender = state.lock().unwrap().download_manager.get_sender();
+    let game_download_agent = Arc::new(Box::new(GameDownloadAgent::new(
+        game_id,
+        game_version,
+        install_dir,
+        sender,
+    )) as Box<dyn Downloadable + Send + Sync>);
+    state
+        .lock()
+        .unwrap()
+        .download_manager
+        .queue_download(game_download_agent)
+        .into()
+}