Replace SortedDictionary with Dictionary in HSSFRow, XSSFRow and SXSSFRow

[tonyqus]

This PR is suggested by OpenCode. It can avoid O(log(n)) scan due to SortedDictionary

Changes

• NPOI won't sort by column number in XXXRow.GetEnumerator anymore for the sake of performance. This can be a breaking change for existing code based on NPOI
• Use a larger buffer in SXSSFWorkbook.CopyStreamAndInjectWorksheet

XSSFWorkbook Benchmark (RowCellAccessBenchmark)

Method	SortedDictionary	Dictionary	Perf Increase
CreateCell_AppendOrder	57,350 ns	39,785 ns	30.6% ⬆️
CreateCell_RandomOrder	70,614 ns	38,459 ns	45.5% ⬆️
GetCell_Existing	38,116 ns	12,290 ns	67.8% ⬆️
IterateAllCells	7,505,841 ns	148,753 ns	98.0% ⬆️
IterateAllCellsWithGetCell	39,033 ns	12,176 ns	68.8% ⬆️
IterateRowCells	498 ns	126 ns	74.7% ⬆️
DeleteCell	62,804 ns	41,003 ns	34.7% ⬆️
ReadCellValues	590,989 ns	501,610 ns	15.1% ⬆️
GetRow_ByIndex	1,744 ns	1,637 ns	6.1% ⬆️
IterateAllRows	3,482 ns	3,534 ns	Same