When the CC field is generated in the UI, the email values are joined together
with ", " but when they are parsed, we currently split by just ",".
This causes an error on the backend and on the frontend.
It seems reasonable to update the code to allow whitespace in the input and to
split by `\s*,\s` and also to trim leading and trailing whitespace from the CC
list.
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Co-authored-by: Sojan <sojan@pepalo.com>
When sending the message with audio, only the signed id of the file is sent.
In the back end check only the UploadedFile type.
The attachment has the default file type image, now it gets the content type from the signed id
Fixes: #5375
Co-authored-by: Sojan Jose <sojan@pepalo.com>
