[GOBBLIN-887] Generialize UniversalKafkaSource to accept Extractor that not extending KafkaExtractor

[autumnust]

Dear Gobblin maintainers,

Please accept this PR. I understand that it will not be reviewed until I have checked off all the steps below!

JIRA

• My PR addresses the following [Gobblin JIRA]
  • https://issues.apache.org/jira/browse/GOBBLIN-887

Description

• Here are some details about my PR, including screenshots (if applicable):

Tests

• My PR adds the following unit tests OR does not need testing for this extremely good reason:

Commits

• My commits all reference JIRA issues in their subject lines, and I have squashed multiple commits if they address the same issue. In addition, my commits follow the guidelines from "How to write a good git commit message":
  1. Subject is separated from body by a blank line
  2. Subject is limited to 50 characters
  3. Subject does not end with a period
  4. Subject uses the imperative mood ("add", not "adding")
  5. Body wraps at 72 characters
  6. Body explains "what" and "why", not "how"

[sv2000]

+1. LGTM.

[codecov-io]

Codecov Report

Merging #2741 into master will increase coverage by <.01%.
The diff coverage is 0%.

@@             Coverage Diff              @@
##             master    #2741      +/-   ##
============================================
+ Coverage     45.18%   45.18%   +<.01%     
- Complexity     8803     8806       +3     
============================================
  Files          1889     1889              
  Lines         70595    70595              
  Branches       7746     7746              
============================================
+ Hits          31897    31900       +3     
+ Misses        35746    35745       -1     
+ Partials       2952     2950       -2

Impacted Files	Coverage Δ	Complexity Δ
.../extractor/extract/kafka/UniversalKafkaSource.java	0% <0%> (ø)	0 <0> (ø)	⬇️
...lin/restli/throttling/ZookeeperLeaderElection.java	70% <0%> (-2.23%)	13% <0%> (ø)
...lin/elasticsearch/writer/FutureCallbackHolder.java	61.42% <0%> (-1.43%)	4% <0%> (ø)
.../org/apache/gobblin/cluster/GobblinTaskRunner.java	64.81% <0%> (+0.46%)	28% <0%> (ø)	⬇️
...e/gobblin/runtime/locks/ZookeeperBasedJobLock.java	64.44% <0%> (+1.11%)	16% <0%> (+1%)	⬆️
...ava/org/apache/gobblin/fsm/FiniteStateMachine.java	76.51% <0%> (+3.03%)	21% <0%> (+3%)	⬆️

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