"Current map bounding box" locale

[Adiorz]

Allow locale for "Current map bounding box" filter and another names in .html files

[nnseva]

Actually it can be localized by the Django i18n subsystem using translation files, as well as "Bounding Box" title. It looks like a Django-way.

https://github.com/nnseva/django-leaflet-admin-list/blob/a5607faf67a23f6b4dc86842faabefb2a76a4f27/leaflet_admin_list/filters.py#L32