Add Statement, QueryExecution and QueryManager

[penghuo]

New abstraction

QueryManager is the high level interface of the core engine, Parser parse raw query as the Plan and sumitted to QueryManager.

1. AstBuilder analyze raw query string and create Statement.
2. QueryPlanFactory create Plan for different Statement.
3. QueryManager execute Plan.

Core engine define the interface of QueryManager. Each execution engine should provide the implementation of QueryManager which bind to execution enviroment.
QueryManager manage all the submitted plans and define the following interface

• submit: submit queryexecution.
• cancel: cancel query execution.
• get: get query execution info of specific query.

Parser parse raw query as Statement and create AbstractPlan. Each AbstractPlan decide how to execute the query in QueryManager.

QueryService is the low level interface of core engine, each Plan decide how to execute the query and use QueryService to analyze, plan, optimize and execute the query.

Change of existing logic

1. Remove the schedule logic in NIO thread. After the change,
   a. Parser will be executed in NIO thread.
   b. QueryManager decide query execution strategy. e.g. OpenSearchQueryManager schedule the QueryExecution running in sql-worker thread pool.

Check List

• New functionality includes testing.
  • All tests pass, including unit test, integration test and doctest
• New functionality has been documented.
  • New functionality has javadoc added
  • New functionality has user manual doc added
• Commits are signed per the DCO using --signoff

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[penghuo]

remove the schedule logic. In OpenSearch, QueryManager will schedule the query in sql-worker thread.

[codecov-commenter]

Codecov Report

Merging #845 (26fc997) into feature/maximus-m1 (63f3449) will decrease coverage by 2.65%.
The diff coverage is 98.97%.

@@                   Coverage Diff                    @@
##             feature/maximus-m1     #845      +/-   ##
========================================================
- Coverage                 97.58%   94.92%   -2.66%     
- Complexity                 3177     3203      +26     
========================================================
  Files                       307      325      +18     
  Lines                      7898     8612     +714     
  Branches                    513      634     +121     
========================================================
+ Hits                       7707     8175     +468     
- Misses                      190      382     +192     
- Partials                      1       55      +54     

Flag	Coverage Δ
query-workbench	62.76% <ø> (?)
sql-engine	97.58% <98.97%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...java/org/opensearch/sql/ppl/parser/AstBuilder.java	100.00% <ø> (ø)
...rg/opensearch/sql/sql/config/SQLServiceConfig.java	100.00% <ø> (ø)
...opensearch/sql/ppl/parser/AstStatementBuilder.java	83.33% <83.33%> (ø)
...g/opensearch/sql/executor/DefaultQueryManager.java	100.00% <100.00%> (ø)
...main/java/org/opensearch/sql/executor/QueryId.java	100.00% <100.00%> (ø)
...java/org/opensearch/sql/executor/QueryService.java	100.00% <100.00%> (ø)
...opensearch/sql/executor/execution/ExplainPlan.java	100.00% <100.00%> (ø)
...g/opensearch/sql/executor/execution/QueryPlan.java	100.00% <100.00%> (ø)
...earch/sql/executor/execution/QueryPlanFactory.java	100.00% <100.00%> (ø)
...ql/opensearch/executor/OpenSearchQueryManager.java	100.00% <100.00%> (ø)
... and 16 more

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