Update PartitionTable to use RowSetBuilder instead of RowSet.insert()

[lbooker42]

Overview:
Use a sequential builder during the creation stage of the PartitionTable since we can rely on ordered keys, transition to using random builder on following updates.

Initial tests show a 30-90% speedup in some cases (data to follow)

Zulu11.54+23-CA (build 11.0.14+9-LTS) on MacOS, M1				
Rows	        Buckets	    partitionBy (ms)	partitionBy_opt (ms)	speedup
100,000,000	100	        1,454	            2,253	                -54.9%
100,000,000	25,000	    95,338	            9,083	                90.5%
100,000,000	1,000,000	30,935	            19,952	                35.5%
				
				
Zulu17.34+19-CA (build 17.0.3+7-LTS) on MacOS, M1				
Rows	        Buckets	    partitionBy (ms)	partitionBy_opt (ms)	speedup
100,000,000	100	        1,500	            2,346	                -56.4%
100,000,000	25,000	    87,767	            8,952	                89.8%
100,000,000	1,000,000	30,993	            19,811	                36.1%

The only regression is in the very large bucket (1M items per bucket) where direct RowSet.insert() is measurably faster. The other cases greatly benefit from these changes however and the overall change is beneficial.

NOTE: It's likely that groupBy() can also benefit from these changes.

[rcaudy]

The changes are generally sound. We can be a little cleaner with allocation.