Implement Documents frontend

DOCUMENTS PAGE
-Export project to TMX
-Search
-Sort (dropdown)
-Show (dropdown)
-Pagination
-Arrow to prev/next page (jump from Lang -> Doc -> Groups and back)
Table
-Name
-% translated
-Last modified (days ago + username)
-progress bar (bottom of row)

Manage Documents and Upload Source Documents appears in mockup but not in Story since the storybook pages only show the container next to the sidebar