TW-1693: delele the encrypted file after downloading it

[sherlockvn]

Demo mobile image + video + encrypted chat / normal chat:

https://drive.google.com/file/d/1UDY0YDVBhkMwULUPO8IaQGh3gg6Tli7T/view?usp=sharing

Demo mobile file when downloading file in encrypted/normal chat:

https://github.com/linagora/twake-on-matrix/assets/43041967/cc4d0cf3-d726-4195-bec3-47faf91608c1

Demo mobile file when sending a file in encrypted/normal chat:

[github-actions[bot]]

This PR has been deployed to https://linagora.github.io/twake-on-matrix/1713

[sherlockvn]

• The files in file_picker folder is duplicated, the best options for now is clear in schedules

  Reason:

  We shouldn't delete the file in this folder during the sending file process, user can click to sending file anytimes, and if we are deleting the files during user open the files, it will have an error. We should find out when we should delete the files in file_picker folder.

[hoangdat]

• The files in file_picker folder is duplicated, the best options for now is clear in schedules

please add it on the description of clean_up ticket. Thank you