Review Time_Agg in group by / group except

[javihern98]

Latest grammar changes in group by/group except adds a new possibility that needs to be reviewed and implemented.

Old grammar:

groupingClause:
    GROUP op=(BY | EXCEPT) componentID (COMMA componentID)*  # groupByOrExcept
    | GROUP ALL exprComponent  # groupAll
    ;

New grammar:

groupingClause:
    GROUP op=(BY | EXCEPT) componentID (COMMA componentID)* ( TIME_AGG LPAREN STRING_CONSTANT (COMMA delim=(FIRST|LAST))? RPAREN )?  # groupByOrExcept
    | GROUP ALL ( TIME_AGG LPAREN STRING_CONSTANT (COMMA delim=(FIRST|LAST))? RPAREN )?  # groupAll 
    ;

Originally posted by @javihern98 in #564 (comment)