[FIX] doc: build errors & some warnings

addons/mass_mailing/static/src/js/mass_mailing_widget.js

addons/web/static/src/js/widgets/name_and_signature.js

addons/web_editor/static/src/js/wysiwyg/plugin/helper.js

...ns/web_editor/static/src/js/wysiwyg/plugin/unbreakable.js

addons/web_editor/static/src/js/wysiwyg/wysiwyg_iframe.js

...editor/static/src/js/wysiwyg_snippets/wysiwyg_snippets.js

doc/_extensions/autojsdoc/parser/jsdoc.py

doc/conf.py