TermPortal: change DE-placeholder for noTermDefinedFor-field in filter-window

noTermDefinedFor-field's DE-placeholder should be changed to 

"Keine Benennung für Sprache vorhanden ("en" findet NICHT "en-US")"

in Filter Window, so that all placeholder text is visible but window widht is kept same to keep support for mobile devices

Other amendments:

1. FilterWindow's the button texts are in English even if gui-language is Deutch. They should be "Abbrechen" instead of "Cancel" and "Filter setzen" instead of "Submit".
2. On the button that opens the filter dialogue, it says "Set filter"/"Filter setzen". The heading of the filter window itself says "Filters/Filter". Heading of the window should have the same texts as on the button.
3. Term translation workflow dialog: change the label of the checkbox, that decides, if already translated terms should be send to translation as follows:
   1. For DE: Bereits übersetzte Benennungen erneut übersetzen lassen?
   2. For EN: Have translated terms retranslated?
4. Change the word "Stapelbearbeitung" to "Stapelverarbeitung", whereever it occurs.