Improve Zip File Error Handling with Instructions (#620)

This PR improves the error handling for zip file operations in the code.
Specifically, it addresses issues related to:

- `BadZipFile` errors, which occur when the downloaded file is corrupted
or not a valid .zip file.
- `FileNotFoundError` for handling cases where the expected file is
missing.
- `RuntimeError` for catching any unexpected errors during file
operations.

Each exception now includes a message that directs users to report the
issue at https://www.github.com/kaggle/kaggle-api.

This enhancement ensures better error reporting and guides users on how
to proceed when encountering problems.

Linked Issue: #619

Author: bzm10

kaggle/api/kaggle_api_extended.py

@@ -1536,8 +1536,16 @@ def dataset_download_files(self,
                         z.extractall(effective_path)
                 except zipfile.BadZipFile as e:
                     raise ValueError(
-                        'Bad zip file, please report on '
-                        'www.github.com/kaggle/kaggle-api', e)
+                        f"The file {outfile} is corrupted or not a valid zip file. "
+                        "Please report this issue at https://www.github.com/kaggle/kaggle-api")
+                except FileNotFoundError:
+                    raise FileNotFoundError(
+                        f"The file {outfile} was not found. "
+                        "Please report this issue at https://www.github.com/kaggle/kaggle-api")
+                except Exception as e:
+                    raise RuntimeError(
+                        f"An unexpected error occurred: {e}. "
+                        "Please report this issue at https://www.github.com/kaggle/kaggle-api")
 
                 try:
                     os.remove(outfile)