feat: map AniDB IDs from Hama agent to tvdb/tmdb/imdb IDs (#538)

* feat: map AniDB IDs from Hama agent to tvdb/tmdb/imdb IDs

re #453

* refactor: removes sync job for AnimeList, load mapping on demand

* refactor: addressing review comments, using typescript types for xml parsing

* refactor: make sure sync job does not update create same tvshow/movie twice

Hama agent can have same tvdbid it for different library items - for example
when user stores different seasons for same tv show separately. This change
adds "AsyncLock" that guarantees code in callback runs for same id fully,
before running same callback next time.

* refactor: do not use season 0 tvdbid for tvshow from mapping file

* refactor: support multiple imdb mappings for same anidb entry

* refactor: add debug log for missing tvdb entries in tmdb lookups from anidb/hama agent

server/api/plexapi.ts

@@ -123,6 +123,14 @@ class PlexAPI {
     return response.MediaContainer.Metadata[0];
   }
 
+  public async getChildrenMetadata(key: string): Promise<PlexMetadata[]> {
+    const response = await this.plexClient.query<PlexMetadataResponse>(
+      `/library/metadata/${key}/children`
+    );
+
+    return response.MediaContainer.Metadata;
+  }
+
   public async getRecentlyAdded(id: string): Promise<PlexLibraryItem[]> {
     const response = await this.plexClient.query<PlexLibraryResponse>(
       `/library/sections/${id}/recentlyAdded`