Lazy initialization of language settings for IME menu

Initialize it only when first time user clicks on it

In a page like Special:Translate where lot of input fields
appearing, the previous approach was adding many language settings
div to the page.

Bug: 48211

Change-Id: If063df6782c6a51ac77ed5531dfa253c7f3ddbc4
Merge "Lazy initialization of language settings for IME menu"