[JS BE] Make sourceMap generation more precise

- Don't produce mapping for closing bracket in case of expressionBody
 - Map Kt*Function declaration into corresponding js fun declaration
 - Update test data & add new test

js/js.translator/testData/lineNumbers/doWhileWithComplexCondition.kt

@@ -13,4 +13,4 @@ fun box() {
     )
 }
 
-// LINES: 14 8 8 7 3 2 2 3 3 3 8 8 11 11 * 3 7 12 3 3 4 4
+// LINES: 1 14 8 8 7 3 2 2 3 3 3 8 8 11 11 * 3 7 12 3 3 4 4