Remove all Zanata-UI dependencies from Glossary container

Remove all zanata UI components from the containers/Glossary/... in frontend:

DeleteAllEntriesModal.jsx
DeleteEntryModal.jsx
Entry.js
EntryModal.js
ExportModal.js
Header.jsx
ImportModal.js
index.jsx
NewEntryModal.js
ViewHeader.js

+ a heap of css tweaks when components are migrated