feat!: add telegram auth and async refactor

- Removed "/schedule/update-download-url" endpoint, this mechanism was replaced by Yandex Cloud FaaS. Ура :)
- Improved schedule caching mechanism.
- Added Telegram WebApp authentication support.
- Reworked endpoints responses and errors mechanism.
- Refactored application state management.
- Make synchronous database operations, middlewares and extractors to asynchronous.
- Made user password field optional to support multiple auth methods.
- Renamed users table column "version" to "android_version" and made it nullable.

src/routes/schedule/teacher.rs

@@ -1,18 +1,11 @@
 use self::schema::*;
-use crate::routes::schema::{IntoResponseAsError, ResponseError};
 use crate::AppState;
+use crate::routes::schema::ResponseError;
 use actix_web::{get, web};
+use schedule_parser::schema::ScheduleEntry;
 
 #[utoipa::path(responses(
-    (status = OK, body = Response),
-    (
-        status = SERVICE_UNAVAILABLE,
-        body = ResponseError<ErrorCode>,
-        example = json!({
-            "code": "NO_SCHEDULE",
-            "message": "Schedule not parsed yet."
-        })
-    ),
+    (status = OK, body = ScheduleEntry),
     (
         status = NOT_FOUND,
         body = ResponseError<ErrorCode>,
@@ -23,72 +16,34 @@ use actix_web::{get, web};
     ),
 ))]
 #[get("/teacher/{name}")]
-pub async fn teacher(
-    name: web::Path<String>,
-    app_state: web::Data<AppState>,
-) -> ServiceResponse {
-    // Prevent thread lock
-    let schedule_lock = app_state.schedule.lock().unwrap();
+pub async fn teacher(name: web::Path<String>, app_state: web::Data<AppState>) -> ServiceResponse {
+    match app_state
+        .get_schedule_snapshot()
+        .await
+        .data
+        .teachers
+        .get(&name.into_inner())
+    {
+        None => Err(ErrorCode::NotFound),
 
-    match schedule_lock.as_ref() {
-        None => ErrorCode::NoSchedule.into_response(),
-        Some(schedule) => match schedule.data.teachers.get(&name.into_inner()) {
-            None => ErrorCode::NotFound.into_response(),
-            Some(entry) => Ok(entry.clone().into()).into(),
-        },
+        Some(entry) => Ok(entry.clone().into()),
     }
+    .into()
 }
 
 mod schema {
-    use schedule_parser::schema::ScheduleEntry;
-    use actix_macros::{IntoResponseErrorNamed, StatusCode};
-    use chrono::{DateTime, NaiveDateTime, Utc};
+    use crate::routes::schedule::schema::ScheduleEntryResponse;
+    use actix_macros::ErrResponse;
     use derive_more::Display;
     use serde::Serialize;
     use utoipa::ToSchema;
 
-    pub type ServiceResponse = crate::routes::schema::Response<Response, ErrorCode>;
+    pub type ServiceResponse = crate::routes::schema::Response<ScheduleEntryResponse, ErrorCode>;
 
-    #[derive(Serialize, ToSchema)]
-    #[schema(as = GetTeacher::Response)]
-    #[serde(rename_all = "camelCase")]
-    pub struct Response {
-        /// Teacher's schedule.
-        pub teacher: ScheduleEntry,
-
-        /// ## Deprecated variable.
-        ///
-        /// By default, an empty list is returned.
-        #[deprecated = "Will be removed in future versions"]
-        pub updated: Vec<i32>,
-
-        /// ## Deprecated variable.
-        ///
-        /// Defaults to the Unix start date.
-        #[deprecated = "Will be removed in future versions"]
-        pub updated_at: DateTime<Utc>,
-    }
-
-    #[allow(deprecated)]
-    impl From<ScheduleEntry> for Response {
-        fn from(teacher: ScheduleEntry) -> Self {
-            Self {
-                teacher,
-                updated: Vec::new(),
-                updated_at: NaiveDateTime::default().and_utc(),
-            }
-        }
-    }
-
-    #[derive(Clone, Serialize, ToSchema, StatusCode, Display, IntoResponseErrorNamed)]
+    #[derive(Clone, Serialize, Display, ToSchema, ErrResponse)]
     #[serde(rename_all = "SCREAMING_SNAKE_CASE")]
     #[schema(as = TeacherSchedule::ErrorCode)]
     pub enum ErrorCode {
-        /// Schedules have not yet been parsed.
-        #[status_code = "actix_web::http::StatusCode::SERVICE_UNAVAILABLE"]
-        #[display("Schedule not parsed yet.")]
-        NoSchedule,
-
         /// Teacher not found.
         #[status_code = "actix_web::http::StatusCode::NOT_FOUND"]
         #[display("Required teacher not found.")]