Detect base64 image to transfer it to CID attachment

[hoangdat]

Desc

• when replying an email which contain base64 image, it makes the replying message bigger than the limit size

DoD

• try to detect any base64 images and transfer it to CID in replying email
• executing it during sending progress
• if we can not transfer it, and it blocks the sending, show explicit error to user aware that
• unit tests
• E2E test in mobile