WP-343: add Grandstream GRP261x series

Reviewed-by: https://github.com/apps/wazo-production-sf

Why: easier to manage function keys

WP-342: add Grandstream GXV33xx

Reviewed-by: https://github.com/apps/wazo-production-sf

Why: the server does not know the certificates

Why: otherwise provd only uses the base.tpl template

WP-353: Add Grandstream GXP16XX

Reviewed-by: https://github.com/apps/wazo-production-sf

Add missing Yealink W90 metadata

Reviewed-by: https://github.com/apps/wazo-production-sf

revert deletion of v83 phone models

Reviewed-by: https://github.com/apps/wazo-production-sf

commit 6abfbe2d

firmware link update

Reviewed-by: https://github.com/apps/wazo-production-sf