Optimize #11087 :
1. In `isReadyToExport`, check if the ip is set. If not, then the user cannot enable xmnote export.
2. Add author field in highlights.
This allows interoperability between different readers who want to
import highlights on different devices/file systems. All that is
needed then to import highlights is to match the local books and
their path based on the checksum.
* Get title, author and number of pages from document's metadata
* Add exportable_title parsed from document's title, used in export file generation.
* JSON: export number of pages
Changed:
- select multiple targets and export to them in a single click.
- local targets (html, json and text) now are timestamped. Exporting booknotes on already exported documents will generate a new file with all the highlights present at export time. Previous files won't be deleted.
Fixed:
- chapters are now correctly represented in html output.
- json issues when exporting the whole history.
- joplin and readwise crashes when they're unable to reach the server
- joplin update notes mechanism.
- joplin is able to recreate the notebook if the user deletes or renames its current one.
- highlights of read-only documents are also added when exporting the whole history (affects mostly android, might affect desktop targets)
Co-authored-by: Utsob Roy <roy@utsob.me>
