Fix failing large note imports

When importing to Vaultwarden (or Bitwarden) notes larger then 10_000
encrypted characters are invalid. This because it for one isn't
compatible with Bitwarden. And some clients tend to break on very large
notes.

We already added a check for this limit when adding a single cipher, but
this caused issues during import, and could cause a partial imported
vault. Bitwarden does some validations before actually running it
through the import process and generates a special error message which
helps the user indicate which items are invalid during the import.

This PR adds that validation check and returns the same kind of error.
Fixes #3048

src/api/core/ciphers.rs

@@ -205,7 +205,7 @@ pub struct CipherData {
     */
     pub Type: i32,
     pub Name: String,
-    Notes: Option<String>,
+    pub Notes: Option<String>,
     Fields: Option<Value>,
 
     // Only one of these should exist, depending on type
@@ -542,6 +542,12 @@ async fn post_ciphers_import(
 
     let data: ImportData = data.into_inner().data;
 
+    // Validate the import before continuing
+    // Bitwarden does not process the import if there is one item invalid.
+    // Since we check for the size of the encrypted note length, we need to do that here to pre-validate it.
+    // TODO: See if we can optimize the whole cipher adding/importing and prevent duplicate code and checks.
+    Cipher::validate_notes(&data.Ciphers)?;
+
     // Read and create the folders
     let mut folders: Vec<_> = Vec::new();
     for folder in data.Folders.into_iter() {