Add feature for TES to indicate that a task was pre-empted

[MattMcL4475]

Problem:
Cromwell has no way to tell if a TES task was preempted

Solution:
Research a TES spec change and implementation to return a pre-empted message to Cromwell to retry with a dedicated machine. For example, a new Tes State could be added for pre-empted. Alternative solutions should be considered.

    /// <summary>
    /// Enum EXECUTORERROREnum for EXECUTOR_ERROR
    /// </summary>
    [EnumMember(Value = "EXECUTOR_ERROR")]
    EXECUTORERROREnum = 7,

    /// <summary>
    /// Enum SYSTEMERROREnum for SYSTEM_ERROR
    /// </summary>
    [EnumMember(Value = "SYSTEM_ERROR")]
    SYSTEMERROREnum = 8,

[ngambani]

@MattMcL4475 @olesya13 do we have any update on this one. Is this something we want to work on or has already been addressed?