RFE: [Fedora] Display translator's preferred/main languages first before other languages

Description of problem:
Most translators master their mother languages better than others. One project may have many languages to be translated; however, zanata should display translators' preferred/main languages first before others to save the time to search for those preferred/main languages.

Version-Release number of selected component (if applicable):

How reproducible:
Always

Steps to Reproduce:
0. Log in as a non-English translator, for example, zh-Hant
1. Enter one project page, for example, fonts-tweak-tool
https://translate.zanata.org/zanata/project/view/fonts-tweak-tool
2. Enter one version page, for example, master
https://translate.zanata.org/zanata/iteration/view/fonts-tweak-tool/master?cid=195174
3. Languages showed to be translated

Actual results:
Languages showed to be translated, sorted by Alphabet
==> Afrikans > Albanian > Amharic...

Expected results:

Suggested as below,
Languages showed to be translated, preferred/main languages first, followed by others which may be later sorted by Alphabet

==> Chinese (Traditional, Taiwan) [translator's main language] ==> Chinese (Taiwan) [translator's main language] ==> Chinese (Simplified) [translator's reference language/preferred language] ==> Japanese [translator's reference language] | Afrikans > Albanian > Amharic...

Additional info: