[FEATURE] Mathematical and Trigonometric functions missing from new V2 engine

[MitchellGale]

Missing Functions from V2 engine

Syntax from https://opensearch.org/docs/latest/search-plugins/sql/functions/.

Missing:

• cosh - Added COSH to V2 engine #1428
• sinh - Added SINH function to V2 engine #1434
• add - Added Arithmetic functions to V2 engine #1416
• subtract - Added Arithmetic functions to V2 engine #1416
• multiply - Added Arithmetic functions to V2 engine #1416
• divide - Added Arithmetic functions to V2 engine #1416
• expm1 - Updated EXPM1() and Tests to New Engine #1334
• rint - Added RINT function to V2 engine  #1433
• signum - Added SIGNUM function to V2 engine #1429
• pow & power - Fix null response from pow/power and added missing integration testing #1457

Can test by adding ifnull(null, true) to where clause which will run query in V2 engine.

opensearchsql> SELECT cosh(0.5) FROM calcs WHERE ifnull(null, true) LIMIT 1;                                                                                                                                                                                
{'reason': 'Invalid SQL query', 'details': 'unsupported method: ifnull', 'type': 'SqlParseException'}