feat(engine): task queries by variables with number values

- querying by number matches variables of any numeric type, i.e. long, int
  short and double

related to CAM-2939
chore(engine): other variable-filtered queries tolerate numbers

- similar to task query, the other queries that can be filtered by
  variables can now be queried by supplying an abstract number value
  that matches short, int, long and double

related to CAM-2939
refactor(engine): task instance query uses historic variable instances

- used historic details before with bugs in checking valid variable values

related to CAM-2939
test(engine): test number queries for all variable-related queries

related to CAM-2939
test(engine): readd previously failing test case
chore(engine-rest): submit Number variable query values

- whenever a query is made that has filtering conditions regarding
  variable values, all numeric values are submitted as values
  of the ValueType 'NUMBER'. This allows querying for all concrete Number
  values regardless of their type, i.e. Short, Integer, Long and Double
  values are matched

related to CAM-2939