Remove empty submodules, fix others

The submodules DataTypes, ValueFormatters, ValueParsers,
ValueValidators, and ValueView have no revisions, which is breaking git
submodule update. Let's delete them; they can be re-added once they
actually contain code.

And the modules WikibaseDatabase and WikibaseQuery are somehow pointing
at non-existent revisions. Update them to master.

Change-Id: If2dbe54e952ea9369c39c051ca4aa4c0de4b5658