- Clarify that enabling server side encryption will not encrypt
existing files but only new or changed files.
- Clarify that server side encryption can only be disabled using OCC
- Ensure there is accessible information of encryption state (`disabled`
input will not be announced so make it `aria-disabled` instead)
- Make warning more prominent by moving it into a dialog
Signed-off-by: Ferdinand Thiessen <opensource@fthiessen.de>