feat(readarr): add the add author handler

Handles the add author search input, search results, and the multi-step
add prompt covering root folder, monitor, monitor new items, quality
profile, metadata profile, tags, and confirmation.

Selecting a search result whose foreign author id already exists in the
library routes to the already-in-library popup instead of the add
prompt, so a duplicate add cannot be submitted.

src/handlers/readarr_handlers/library/library_handler_tests.rs

@@ -14,8 +14,8 @@ mod tests {
   use crate::models::HorizontallyScrollableText;
   use crate::models::readarr_models::{Author, AuthorStatistics, AuthorStatus};
   use crate::models::servarr_data::readarr::readarr_data::{
-    AUTHOR_DETAILS_BLOCKS, ActiveReadarrBlock, BOOK_DETAILS_BLOCKS, EDITION_DETAILS_BLOCKS,
-    LIBRARY_BLOCKS,
+    ADD_AUTHOR_BLOCKS, AUTHOR_DETAILS_BLOCKS, ActiveReadarrBlock, BOOK_DETAILS_BLOCKS,
+    EDITION_DETAILS_BLOCKS, LIBRARY_BLOCKS,
   };
   use crate::test_handler_delegation;
 
@@ -889,6 +889,15 @@ mod tests {
     );
   }
 
+  #[test]
+  fn test_delegates_add_author_blocks_to_add_author_handler() {
+    test_handler_delegation!(
+      LibraryHandler,
+      ActiveReadarrBlock::Authors,
+      ActiveReadarrBlock::AddAuthorSearchInput
+    );
+  }
+
   #[test]
   fn test_library_handler_accepts() {
     let mut library_handler_blocks = Vec::new();
@@ -896,6 +905,7 @@ mod tests {
     library_handler_blocks.extend(AUTHOR_DETAILS_BLOCKS);
     library_handler_blocks.extend(BOOK_DETAILS_BLOCKS);
     library_handler_blocks.extend(EDITION_DETAILS_BLOCKS);
+    library_handler_blocks.extend(ADD_AUTHOR_BLOCKS);
 
     ActiveReadarrBlock::iter().for_each(|readarr_block| {
       if library_handler_blocks.contains(&readarr_block) {