feat(all): Task store

implements:
https://github.com/meilisearch/specifications/blob/develop/text/0060-refashion-updates-apis.md

linked PR:

- #1889
- #1891
- #1892
- #1902
- #1906
- #1911
- #1914
- #1915
- #1916
- #1918
- #1924
- #1925
- #1926
- #1930
- #1936
- #1937
- #1942
- #1944
- #1945
- #1946
- #1947
- #1950
- #1951
- #1957
- #1959
- #1960
- #1961
- #1962
- #1964

- https://github.com/meilisearch/milli/pull/414
- https://github.com/meilisearch/milli/pull/409
- https://github.com/meilisearch/milli/pull/406
- https://github.com/meilisearch/milli/pull/418

- close #1687
- close #1786
- close #1940
- close #1948
- close #1949
- close #1932
- close #1956

meilisearch-lib/src/tasks/error.rs

@@ -0,0 +1,33 @@
+use meilisearch_error::{Code, ErrorCode};
+use tokio::task::JoinError;
+
+use crate::update_file_store::UpdateFileStoreError;
+
+use super::task::TaskId;
+
+pub type Result<T> = std::result::Result<T, TaskError>;
+
+#[derive(Debug, thiserror::Error)]
+pub enum TaskError {
+    #[error("Task `{0}` not found.")]
+    UnexistingTask(TaskId),
+    #[error("Internal error: {0}")]
+    Internal(Box<dyn std::error::Error + Send + Sync + 'static>),
+}
+
+internal_error!(
+    TaskError: heed::Error,
+    JoinError,
+    std::io::Error,
+    serde_json::Error,
+    UpdateFileStoreError
+);
+
+impl ErrorCode for TaskError {
+    fn error_code(&self) -> Code {
+        match self {
+            TaskError::UnexistingTask(_) => Code::TaskNotFound,
+            TaskError::Internal(_) => Code::Internal,
+        }
+    }
+}