[Backport 2.x] Add Timestampdiff Function To OpenSearch SQL

[opensearch-trigger-bot]

Backport 31148da from #1467

[codecov-commenter]

Codecov Report

Merging #1472 (b9a568b) into 2.x (49a82ae) will increase coverage by 0.00%.
The diff coverage is 100.00%.

📣 This organization is not using Codecov’s GitHub App Integration. We recommend you install it so Codecov can continue to function properly for your repositories. Learn more

@@            Coverage Diff            @@
##                2.x    #1472   +/-   ##
=========================================
  Coverage     98.46%   98.46%           
- Complexity     3848     3863   +15     
=========================================
  Files           345      345           
  Lines          9554     9594   +40     
  Branches        615      615           
=========================================
+ Hits           9407     9447   +40     
  Misses          142      142           
  Partials          5        5           

Flag	Coverage Δ
sql-engine	98.46% <100.00%> (+<0.01%)	⬆️

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

Impacted Files	Coverage Δ
...c/main/java/org/opensearch/sql/expression/DSL.java	100.00% <100.00%> (ø)
...arch/sql/expression/datetime/DateTimeFunction.java	100.00% <100.00%> (ø)
...h/sql/expression/function/BuiltinFunctionName.java	100.00% <100.00%> (ø)
...pensearch/sql/sql/parser/AstExpressionBuilder.java	100.00% <100.00%> (ø)

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.