Use name and alias in JDBC format

[dai-chen]

Issue #, if available: #939

Description of changes:

SQL:

1. NamedExpression: getName is renamed as getNameOrAlias. Now getName is just the getter for name.
2. ProjectOperator always use original text (NamedExpression's name) as name in QueryResult: JDBC formatter returns both name and alias in response for client side to use.
3. QueryResult uses name or alias as column name when iterated: Simple JSON formatter (PPL) and CSV formatter iterates QueryResult and uses it.

SQL-CLI:

1. Use alias as table header if present in schema in response: since alias is used only when it's present, there should be no impact on PPL response.
2. Depends on local sql-cli directly in doctest module: in this way, no need to push sql-cli artifact to PyPi manually whenever changed.

Testing:

1. SQL: Added UT and IT. Fixed broken UT and IT.
2. CLI's UT and IT passed:

# Build and install in virtualenv
$ cd sql-cli
$ pip install virtualenv
$ virtualenv venv
$ source ./venv/bin/activate
(venv) $ pip install --editable .

# Run tests
(venv) $ pip install -r requirements-dev.txt
(venv) $ cd tests
(venv) $ pytest
========================================================================================= test session starts ==========================================================================================
platform darwin -- Python 3.7.4, pytest-4.6.3, py-1.10.0, pluggy-0.13.1
rootdir: /Users/daichen/IdeaProjects/sql/sql-cli/tests, inifile: pytest.ini
collected 29 items

test_config.py ...                                                                                                                                                                               [ 10%]
test_esconnection.py ........                                                                                                                                                                    [ 37%]
test_formatter.py ..............                                                                                                                                                                 [ 86%]
test_main.py ..                                                                                                                                                                                  [ 93%]
test_odfesql_cli.py .s                                                                                                                                                                           [100%]

================================================================================= 28 passed, 1 skipped in 3.29 seconds =================================================================================

# Exit virtualenv
(venv) $ deactivate
$ ...

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[codecov]

Codecov Report

Merging #932 (a3e5420) into develop (ca9f578) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             develop     #932   +/-   ##
==========================================
  Coverage      99.86%   99.86%           
- Complexity      2334     2336    +2     
==========================================
  Files            232      232           
  Lines           5376     5379    +3     
  Branches         350      350           
==========================================
+ Hits            5369     5372    +3     
  Misses             5        5           
  Partials           2        2           

Impacted Files	Coverage Δ	Complexity Δ
...ndistroforelasticsearch/sql/analysis/Analyzer.java	100.00% <100.00%> (ø)	44.00 <0.00> (ø)
...rch/sql/analysis/ExpressionReferenceOptimizer.java	100.00% <100.00%> (ø)	12.00 <0.00> (ø)
...relasticsearch/sql/expression/NamedExpression.java	100.00% <100.00%> (ø)	6.00 <1.00> (ø)
...arch/sql/planner/physical/AggregationOperator.java	100.00% <100.00%> (ø)	7.00 <0.00> (ø)
...icsearch/sql/planner/physical/ProjectOperator.java	100.00% <100.00%> (ø)	7.00 <0.00> (ø)
...ge/script/aggregation/AggregationQueryBuilder.java	100.00% <100.00%> (ø)	7.00 <1.00> (ø)
...ript/aggregation/dsl/BucketAggregationBuilder.java	100.00% <100.00%> (ø)	3.00 <0.00> (ø)
...asticsearch/sql/protocol/response/QueryResult.java	100.00% <100.00%> (ø)	8.00 <3.00> (+2.00)

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[zhongnansu]

LGTM