l10n: Add svn2git rules to import l10n*/scripts/ from SVN

Test Plan: svn2git produces a good enough Git repository.

Reviewers: Localization, aacid, ltoscano, pino, nalvarez

Subscribers: bcooksley, nalvarez, pino, ltoscano, aacid, Localization

Maniphest Tasks: T4803

Differential Revision: https://phabricator.kde.org/D25929