Refactor FT.AGGREGATE reducers to process records in batch

[AlexFilipImproving]

Changed the ProcessRecords interface to accept all records at once instead of processing them one at a time. This enables more efficient implementations, particularly for COUNT which now simply returns the input size rather than incrementing a counter for each record.

Changes:

• Updated ReducerInstance::ProcessRecords to accept const std::vector<absl::InlinedVector<expr::Value, 4>>& all_values
• Modified GroupBy::Execute to collect all values per group before calling ProcessRecords once
• Updated all reducer implementations (Count, Min, Max, Sum, Avg, Stddev, CountDistinct) to process batched records

[AlexFilipImproving]

I also added a cleanup of the sortby_parameter added in my previous PR

[AlexFilipImproving]

I made the requested changes, but it looks like some of the compatibility tests are failing for reasons outside of this change. For example, these look like they have to do with the implementation of DIALECT 2

>>>>>>>>>>> ERROR FAILURE <<<<<<<<<<<<<<
>>>>>> Starting Test test_bad_numeric_data[json-2] So Far: Correct:0 Wrong:1 <<<<<<<<<
CMD: b'ft.search json_idx1 @n1:[-inf inf] DIALECT 2'
CMD:['ft.search', 'json_idx1', '@n1:[-inf inf]', 'DIALECT', '2']
Mismatched sizes RL:2 VK:3
--RL--
{'__key': b'json:0', '$': b'{"n1":0,"n2":0,"n3":0,"t1":"","t2":"","t3":"","v1":[0,0,0],"e1":1,"e2":"two"}'}
{'__key': b'json:4', '$': b'{"n1":0,"n2":0,"n3":0,"t2":"","t3":"","v1":[4,4,4],"e1":1,"e2":"two"}'}
--VK:--
{'__key': b'json:0', '$': b'{"n1":0,"n2":0,"n3":0,"t1":"","t2":"","t3":"","v1":[0,0,0],"e1":1,"e2":"two"}'}
{'__key': b'json:4', '$': b'{"n1":0,"n2":0,"n3":0,"t2":"","t3":"","v1":[4,4,4],"e1":1,"e2":"two"}'}
{'__key': b'json:5', '$': b'{"n1":0,"n2":0,"n3":0,"t2":"","t3":"","v1":[5,5,5,5]}'}
>>>>>>>>>>> ERROR FAILURE <<<<<<<<<<<<<<
>>>>>> Starting Test test_bad_numeric_data[json-2] So Far: Correct:0 Wrong:2 <<<<<<<<<
CMD: b'ft.search json_idx1 @n1:[-inf inf] DIALECT 2'
CMD:['ft.search', 'json_idx1', '@n1:[-inf inf]', 'DIALECT', '2']
Mismatched sizes RL:2 VK:3
--RL--
{'__key': b'json:0', '$': b'{"n1":0,"n2":0,"n3":0,"t1":"","t2":"","t3":"","v1":[0,0,0],"e1":1,"e2":"two"}'}
{'__key': b'json:4', '$': b'{"n1":0,"n2":0,"n3":0,"t2":"","t3":"","v1":[4,4,4],"e1":1,"e2":"two"}'}
--VK:--
{'__key': b'json:0', '$': b'{"n1":0,"n2":0,"n3":0,"t1":"","t2":"","t3":"","v1":[0,0,0],"e1":1,"e2":"two"}'}
{'__key': b'json:4', '$': b'{"n1":0,"n2":0,"n3":0,"t2":"","t3":"","v1":[4,4,4],"e1":1,"e2":"two"}'}
{'__key': b'json:5', '$': b'{"n1":0,"n2":0,"n3":0,"t2":"","t3":"","v1":[5,5,5,5]}'}

[BCathcart]

@boda26 Mind taking a look at the failing compatibility test? I was wondering if it was my recent change but this looks like a basic numeric search which should be unaffected

[BCathcart]

Failures probably fixed by #838