The files that are pasted or dropped over the editor should be uploaded as attachments of the edited page

Pasting  / dropping a file should upload that file as an attachment of the edited page and then insert the corresponding block in the edited content (e.g. an image block for an image). The inserted block should reference the attached (internal) file.

We currently get this warning:

Attempted ot insert file, but uploadFile is not set in the BlockNote editor options

We also need to check how BlockNote handles the async upload of the time. The end user needs to be aware that the pasted / dropped file is currently being uploaded (ideally with a progress bar).

There might be cases when the pasted file doesn't have a name (and we need one to be able to upload the file as an attachment). We probably want to ask the user for a name in this case, with a fallback on some default generated name.

There is also the case of pasting HTML that includes images. We may want to provide the user the option to unload the referenced external images as page attachments, but this might deserve a separate JIRA issue.