perf: reduce temp allocation in deserialization

[proost]

In deserialization, current temp allocation happens. we can reduce that.
And we can reduce two loops into one loop.

ItemsSketch

main:

goos: darwin
goarch: arm64
pkg: github.com/apache/datasketches-go/frequencies
cpu: Apple M4 Pro
BenchmarkItemsSketchFromSlice
BenchmarkItemsSketchFromSlice/int64/items=48
BenchmarkItemsSketchFromSlice/int64/items=48-12         	 1298882	       908.8 ns/op	 880.28 MB/s	    2096 B/op	       7 allocs/op
BenchmarkItemsSketchFromSlice/int64/items=192
BenchmarkItemsSketchFromSlice/int64/items=192-12        	  327068	      3683 ns/op	 842.75 MB/s	    7856 B/op	       7 allocs/op
BenchmarkItemsSketchFromSlice/int64/items=768
BenchmarkItemsSketchFromSlice/int64/items=768-12        	   78704	     15302 ns/op	 805.14 MB/s	   30896 B/op	       7 allocs/op
BenchmarkItemsSketchFromSlice/string/items=48
BenchmarkItemsSketchFromSlice/string/items=48-12        	  770403	      1510 ns/op	 618.69 MB/s	    3632 B/op	      55 allocs/op
BenchmarkItemsSketchFromSlice/string/items=192
BenchmarkItemsSketchFromSlice/string/items=192-12       	  201334	      6039 ns/op	 622.92 MB/s	   13872 B/op	     199 allocs/op
BenchmarkItemsSketchFromSlice/string/items=768
BenchmarkItemsSketchFromSlice/string/items=768-12       	   48657	     24591 ns/op	 621.44 MB/s	   54704 B/op	     775 allocs/op
PASS

PR:

goos: darwin
goarch: arm64
pkg: github.com/apache/datasketches-go/frequencies
cpu: Apple M4 Pro
BenchmarkItemsSketchFromSlice
BenchmarkItemsSketchFromSlice/int64/items=48
BenchmarkItemsSketchFromSlice/int64/items=48-12         	 1419704	       845.1 ns/op	 946.62 MB/s	    1712 B/op	       6 allocs/op
BenchmarkItemsSketchFromSlice/int64/items=192
BenchmarkItemsSketchFromSlice/int64/items=192-12        	  342088	      3459 ns/op	 897.38 MB/s	    6320 B/op	       6 allocs/op
BenchmarkItemsSketchFromSlice/int64/items=768
BenchmarkItemsSketchFromSlice/int64/items=768-12        	   82773	     14514 ns/op	 848.81 MB/s	   24752 B/op	       6 allocs/op
BenchmarkItemsSketchFromSlice/string/items=48
BenchmarkItemsSketchFromSlice/string/items=48-12        	  803619	      1447 ns/op	 645.27 MB/s	    3248 B/op	      54 allocs/op
BenchmarkItemsSketchFromSlice/string/items=192
BenchmarkItemsSketchFromSlice/string/items=192-12       	  207325	      5827 ns/op	 645.62 MB/s	   12336 B/op	     198 allocs/op
BenchmarkItemsSketchFromSlice/string/items=768
BenchmarkItemsSketchFromSlice/string/items=768-12       	   50332	     23517 ns/op	 649.84 MB/s	   48560 B/op	     774 allocs/op
PASS

LongsSketch

main:

goos: darwin
goarch: arm64
pkg: github.com/apache/datasketches-go/frequencies
cpu: Apple M4 Pro
BenchmarkLongsSketchFromSlice
BenchmarkLongsSketchFromSlice/items=48
BenchmarkLongsSketchFromSlice/items=48-12         	 2753096	       429.0 ns/op	1864.97 MB/s	    2064 B/op	       7 allocs/op
BenchmarkLongsSketchFromSlice/items=192
BenchmarkLongsSketchFromSlice/items=192-12        	  774289	      1511 ns/op	2053.71 MB/s	    7824 B/op	       7 allocs/op
BenchmarkLongsSketchFromSlice/items=768
BenchmarkLongsSketchFromSlice/items=768-12        	  208054	      5727 ns/op	2151.25 MB/s	   30864 B/op	       7 allocs/op
PASS

PR:

goos: darwin
goarch: arm64
pkg: github.com/apache/datasketches-go/frequencies
cpu: Apple M4 Pro
BenchmarkLongsSketchFromSlice
BenchmarkLongsSketchFromSlice/items=48
BenchmarkLongsSketchFromSlice/items=48-12         	 3277532	       352.7 ns/op	2268.47 MB/s	    1296 B/op	       5 allocs/op
BenchmarkLongsSketchFromSlice/items=192
BenchmarkLongsSketchFromSlice/items=192-12        	  978699	      1265 ns/op	2453.94 MB/s	    4752 B/op	       5 allocs/op
BenchmarkLongsSketchFromSlice/items=768
BenchmarkLongsSketchFromSlice/items=768-12        	  247640	      4888 ns/op	2520.38 MB/s	   18576 B/op	       5 allocs/op
PASS