Add bulk release/file yank and delete actions in project management

[Trighap52]

Summary

• add bulk selection checkboxes and action forms on manage release pages for releases and files
• add POST handlers for bulk release yank/unyank/delete and bulk file deletion
• preserve existing confirmation and deletion-flag checks for bulk operations
• add unit tests for success paths and validation/error paths
• update translation references after adding new translatable strings

Closes #19469.

Validation

• make lint
• T=tests/unit/manage/test_views.py make tests