fix(blacklist): request data only when modal is shown, remove useless ratelimit and lazy load blacklist (#1084)

* perf: remove eager load of Blacklist entity from Media entity

Try to resolve some performance issues by removing the eager loading of Blacklist items from the
Media entity

* fix: fix ManageSlideOver for blacklist

* perf(blacklist): request data only when modal is shown

For admin users, the button to blacklist a media (used on every media card) was displaying a Modal,
that was requesting data BEFORE the modal was displayed. This resulted in dozens of additional
requests everytime media cards were displayed.

* perf(blacklist): remove useless ratelimit

overseerr-api.yml

@@ -4142,6 +4142,21 @@ paths:
         '412':
           description: Item has already been blacklisted
   /blacklist/{tmdbId}:
+    get:
+      summary: Get media from blacklist
+      tags:
+        - blacklist
+      parameters:
+        - in: path
+          name: tmdbId
+          description: tmdbId ID
+          required: true
+          example: '1'
+          schema:
+            type: string
+      responses:
+        '200':
+          description: Blacklist details in JSON
     delete:
       summary: Remove media from blacklist
       tags: