feat(readarr): add the delete author handler

Handles the delete author prompt, toggling whether to delete files on
disk and whether to add a list exclusion before confirming.

Backing out of the prompt resets both toggles, so preferences from an
abandoned delete cannot leak into the next one.

src/handlers/readarr_handlers/library/library_handler_tests.rs

@@ -15,7 +15,7 @@ mod tests {
   use crate::models::readarr_models::{Author, AuthorStatistics, AuthorStatus};
   use crate::models::servarr_data::readarr::readarr_data::{
     ADD_AUTHOR_BLOCKS, AUTHOR_DETAILS_BLOCKS, ActiveReadarrBlock, BOOK_DETAILS_BLOCKS,
-    EDIT_AUTHOR_BLOCKS, EDITION_DETAILS_BLOCKS, LIBRARY_BLOCKS,
+    DELETE_AUTHOR_BLOCKS, EDIT_AUTHOR_BLOCKS, EDITION_DETAILS_BLOCKS, LIBRARY_BLOCKS,
   };
   use crate::test_handler_delegation;
 
@@ -898,6 +898,15 @@ mod tests {
     );
   }
 
+  #[test]
+  fn test_delegates_delete_author_blocks_to_delete_author_handler() {
+    test_handler_delegation!(
+      LibraryHandler,
+      ActiveReadarrBlock::Authors,
+      ActiveReadarrBlock::DeleteAuthorPrompt
+    );
+  }
+
   #[test]
   fn test_delegates_edit_author_blocks_to_edit_author_handler() {
     test_handler_delegation!(
@@ -915,6 +924,7 @@ mod tests {
     library_handler_blocks.extend(BOOK_DETAILS_BLOCKS);
     library_handler_blocks.extend(EDITION_DETAILS_BLOCKS);
     library_handler_blocks.extend(ADD_AUTHOR_BLOCKS);
+    library_handler_blocks.extend(DELETE_AUTHOR_BLOCKS);
     library_handler_blocks.extend(EDIT_AUTHOR_BLOCKS);
 
     ActiveReadarrBlock::iter().for_each(|readarr_block| {