Fix missing FILTER parenthesis

[simeonackermann]

Add closing parenthesis at the end of the FILTER lang and datatype

[pfrischmuth]

• [x] manual review commits
• [x] check unit tests: Tests: 648, Assertions: 1307, Incomplete: 3, Skipped: 1.
• [x] check integration tests mysql: Tests: 63, Assertions: 5834, Skipped: 7.
• [x] check integration tests virtuoso: Tests: 63, Assertions: 224, Skipped: 9.

OK