EmailSender plugin should support non-file attachments

[rtholmes]

MessageBuilder can also take Attachment(s) that can be constructed from strings (or byte arrays):

https://developer.blackberry.com/native/reference/cascades/bb__pim__message__attachment.html#function-attachment-mimetype-name-textdata

Supporting attachments in this way would be beneficial because it would allow webworks apps to append attachments to emails without requiring 'Shared File' permissions (currently the invoke card for email requires a path to the shared directory for attachments; private app storage cannot be used).

[timwindsor]

Added by #340

[rtholmes]

Just checking: in the end this just added the ability to specify attachments by path right? I think this was previously supported by blackberry.invoke.card.invokeEmailComposer without the plugin. This original bug was about being able to supply an attachment as a stream of data instead of a path to a file. This would permit attachments to be generated by apps and attached without requiring the access_shared permission to be set.

[timwindsor]

Weird, for some reason I thought that had been included already. This does allow files to be included from the App's private filesystem, so it does bypass the need to use the shared folder. I'll reopen it though so that we can add the byte array feature.

[rtholmes]

Thanks Tim. Since it is already using MessageBuilder under the covers, I think it would just be a 30 minute fix to allow a var to be passed containing what would be the contents of a text file or the base64 of an image.

[timwindsor]

All right, please check out the latest push and see how it works for you.