[class-parse] Use BufferedStream for up to 10x performance gain

[jpobst]

While building AndroidX.sln, class-parse is taking up a considerable amount of time. After some quick profiling, this seems to be caused by reading from a ZipStream one or two bytes at a time. Wrapping the ZipStream in a BufferedStream makes the class-parse process about 10x faster on larger test cases.

	main	This PR
class-parse on API-33 android.jar (26.5 MB)	16.675s	2.759s
class-parse on androidx.compose.runtime.runtime (1.044 MB)	9.713s	.893s
Total class-parse time building AndroidX.sln	5:48.46m	2:09.73m
Total time building AndroidX.sln	7:40.19m	4:42.34m