Enable localizers to propose new terms

[bugzilla-to-github]

This issue was created automatically by a script.

Bug 1728297

Bug Reporter: @mathjazz

Localizers should have the ability to propose new terms to be added to the glossary.

Once the proposed terms are approved by the admins (we already have that ability in the Admin), they will appear in the translation UI.

We should consider making this feature optional as different instances might have different rules of terminology management.

[Ibragimov]

That would could be great to have an ability to add new terms or terminology manually or by selecting source term and target term and copying them to the "add new term editor" by pressing a shortcut or add new term button, select category (noun, verb, adjective, plural form, button, title etc), edit both terms if necessary before the submit.

Also that would be handy to see terminology from other locales for reference on TERMS tab as subtab or autosearch by locale codes.

Connect Wikipedia (WIKIPEDIA tab along with TERMS|WIKIPEDIA|COMMENTS to search for more information and get more reference?