fix task: atomic update/get fields and re-schedule

[javeme]

• atomic update and get task status&result
• call resubmitTask() when re-schedule task

Change-Id: Iae736b875e2796206e29360da1ecb8aa457fbbed

[codecov]

Codecov Report

Merging #1361 (9d81eda) into master (7f63b57) will decrease coverage by 0.01%.
The diff coverage is 20.00%.

@@             Coverage Diff              @@
##             master    #1361      +/-   ##
============================================
- Coverage     62.38%   62.37%   -0.02%     
  Complexity     5817     5817              
============================================
  Files           385      385              
  Lines         31922    31928       +6     
  Branches       4451     4453       +2     
============================================
- Hits          19916    19915       -1     
- Misses         9984     9989       +5     
- Partials       2022     2024       +2     

Impacted Files	Coverage Δ	Complexity Δ
...om/baidu/hugegraph/task/StandardTaskScheduler.java	76.10% <0.00%> (-1.34%)	85.00 <0.00> (ø)
...in/java/com/baidu/hugegraph/task/TaskCallable.java	55.88% <0.00%> (ø)	13.00 <0.00> (ø)
...c/main/java/com/baidu/hugegraph/task/HugeTask.java	69.84% <33.33%> (-0.10%)	82.00 <0.00> (ø)

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