Don't check for older messages with same msgid
we can't rely on a message's `id` attribute being unique.

Also, remove `createMessage` in favour of calling `messages.create` directly.

updates #1405

Fixes #1405

Updates #1442

* change jcbrand to conversejs in releases links

- Combine all test init functions into `initConverse`
- Use `async` functions in more tests
- Replace `var` with `let` and `const` in more tests
- New utils method `toStanza` which converts a string to a Node

'dependencies' in package.json get installed as well when installing
converse.js or @converse/headless in a 3rd party project, which is
unnecessary.

And fix an extra space added by mistake by the sed command on
_converse.VERSION_NAME in converse-core.js.

Add the version to the archive name so it also fixes #1375.
Remove the recipes for css/webfonts.zip, sounds.zip, and locale.zip.

Fixes #1414

Fixes #1431.

The option got lost in commit 9528d81c.

Fixes #1263

Currently translated at 60.4% (226 of 374 strings)

Translation: Converse.js/Translations
Translate-URL: https://hosted.weblate.org/projects/conversejs/translations/he/

Currently translated at 100.0% (374 of 374 strings)

Translation: Converse.js/Translations
Translate-URL: https://hosted.weblate.org/projects/conversejs/translations/de/

Currently translated at 11.2% (42 of 374 strings)

Translation: Converse.js/Translations
Translate-URL: https://hosted.weblate.org/projects/conversejs/translations/hi/

Currently translated at 93.9% (351 of 374 strings)

Translation: Converse.js/Translations
Translate-URL: https://hosted.weblate.org/projects/conversejs/translations/ja/

Translated using Weblate (Esperanto)

Currently translated at 50.0% (187 of 374 strings)

Translation: Converse.js/Translations
Translate-URL: https://hosted.weblate.org/projects/conversejs/translations/eo/