Update vietnam translation (#2167)

* Updated vietnam translation:
* complete translation the entryfield for BibTex and BibLaTex
 * insert new localization.lang keys
* complete translation for shared database

* Rechanged the translation for date

* Revert class:
* EntryEditorTab.java
* FieldExtraComponents.java
* EntryLinkListEditor.java

CHANGELOG.md

@@ -63,6 +63,7 @@ We refer to [GitHub issues](https://github.com/JabRef/jabref/issues) by using `#
 - Customized importer files need to be slightly changed since the class `ImportFormat` was renamed to `Importer`
 - [koppor#5](https://github.com/koppor/jabref/issues/5) When entries are found while dropping a pdf with xmp meta data the found entries will be displayed in the import dialog
 - [koppor#61](https://github.com/koppor/jabref/issues/61) Display gray background text in "Author" and "Editor" field to assist newcomers
+- Updated Vietnam translation
 
 ### Fixed
 - Fixed [#2089](https://github.com/JabRef/jabref/issues/2089): Fixed faulty cite key generation