refactor(engine-rest): change signature of GET variable-instance

- change JSON response of variable instance queries to not have two
  separated fields value and serializedValue but only have one
  field value because the two are anyway mutually exclusive

related to CAM-2435
feat(engine-rest): set execution/task variables from serialized

- allows to set variables from their serialized representation
  if a variable type is provided and the update does not match
  a "primitive" variable operation (i.e. the value is a standard JDK
  class)
- allows to set Serializable variables from a serialized representation
  by POSTing a byte array

related to CAM-2634
chore(engine-rest): undo deprecation of binary variable value paths

- makes the API inconsistent otherwise

related to CAM-2634
chore(engine): throw exception if outside of commandContext

- SerializationType needs the command context for variable instances
- SpinSerializationType doesn't need the command context at all and
  it doesn't indicates whether the deserialization will work or not

related to #CAM-2435
fix(engine): fix typo in historic variable instance getter
chore(rest): add value type name field for historic variable update

related to #CAM-2435
chore(rest): refactor mock provider/builder

related to #CAM-2435
chore(engine): rename spin serialization type

- spin serialization type is now lower case and with hyphens
- the exception message contains a hint to the
  'defaultSerializationFormat' configuration if the spin serialization
  type is not available
chore(rest): fix function names and exception type

related to #CAM-2634
wip(engine): add filter entity, manager and service

related to #CAM-2628
wip(engine): add task query to json converter

related to #CAM-2628
wip(engine): execute filters
wip
wip: extend filter with queries
wip