Make breadcrumbs text more intuitive on the creation of new entities in Projects (2/2)

Problem to be solved

• Adherence to the Pajamas design system guidelines for using intuitive breadcrumbs text: https://design.gitlab.com/components/breadcrumb#special-breadcrumbs
• Localizability / translatability, as described in the comments thread on the original merge request: !119153 (comment 1664262088)

User problem

This will solve the problem of the English text being seemingly terse, short, vague, and non-intuitive, which in its turn has caused the questions back-and-forth from the wider community of translators of GitLab product, who reported the difficult-next-to-impossible way to reflect the intent of the original English in their target languages.

Proposal

Instead of the breadcrumb text New, make it more descriptive.

• Group > Project > Merge requests > New merge request (app/views/projects/merge_requests/creations/new.html.haml)
• Group > Project > Labels > New snippet (app/views/projects/snippets/new.html.haml)

More details on the localizability problem

Details are provided in comment thread here: !119153 (comment 1664262088)

Summary: New in English is a loosely used adjective that implies a noun that follows (environment, release), but explicitly omits it. Omission creates ambiguity in terms of intuitive understanding, and in terms of translatability, where translators have to guess the following noun, as in "What is New talking about, and what should I use, Nouveau, Nouvel, or Nouvelle...?", and even if they do understand the implied noun and translate New as Nouvelle, the standalone Nouvelle may sound un-intuitively loose in French, and similarly in other languages.