Merge #2982

2982: Adapt task queries to account for special index swap rules r=irevoire a=loiclec

# Pull Request

## Related issue
Fixes https://github.com/meilisearch/meilisearch/issues/2970 

## What does this PR do?
- Replace the `get_tasks` method with a `get_tasks_from_authorized_indexes` which returns the list of tasks matched by the query **from the point of view of the user**. That is, it takes into consideration the list of authorised indexes as well as the special case of `IndexSwap` which should not be returned if an index_uid is specified or if any of its associated indexes are not authorised.
- Adapt the code in other places following this change
- Add some tests
- Also the method `get_task_ids_from_authorized_indexes` now takes a read transaction as argument. This is because we want to make sure that the implementation of `get_tasks_from_authorized_indexes` only uses one read transaction. Otherwise, we could (1) get a list of task ids matching the query, then (2) one of these task ids is deleted by a taskDeletion task, and finally (3) we try to get the `Task`s associated with each returned task ids, and get a `CorruptedTaskQueue` error.



Co-authored-by: Loïc Lecrenier <loic.lecrenier@me.com>

meilisearch-http/src/routes/indexes/mod.rs

@@ -1,11 +1,11 @@
 use actix_web::web::Data;
 use actix_web::{web, HttpRequest, HttpResponse};
-use index_scheduler::{IndexScheduler, Query};
+use index_scheduler::IndexScheduler;
 use log::debug;
 use meilisearch_types::error::ResponseError;
 use meilisearch_types::index_uid::IndexUid;
 use meilisearch_types::milli::{self, FieldDistribution, Index};
-use meilisearch_types::tasks::{KindWithContent, Status};
+use meilisearch_types::tasks::KindWithContent;
 use serde::{Deserialize, Serialize};
 use serde_json::json;
 use time::OffsetDateTime;
@@ -202,14 +202,7 @@ impl IndexStats {
         index_uid: String,
     ) -> Result<Self, ResponseError> {
         // we check if there is currently a task processing associated with this index.
-        let processing_task = index_scheduler.get_tasks(Query {
-            status: Some(vec![Status::Processing]),
-            index_uid: Some(vec![index_uid.clone()]),
-            limit: Some(1),
-            ..Query::default()
-        })?;
-        let is_processing = !processing_task.is_empty();
-
+        let is_processing = index_scheduler.is_index_processing(&index_uid)?;
         let index = index_scheduler.index(&index_uid)?;
         let rtxn = index.read_txn()?;
         Ok(IndexStats {