HDDS-15592 use heap allocation in ChunkBuffer

[yandrey321]

What changes were proposed in this pull request?

When ChunkBuffer allocates heap buffer UnsafeByteOperations.unsafeWrap() returns a BoundedByteString with a backing array, enabling a single System.arraycopy into the gRPC/Netty wire buffer instead of the slow byte-by-byte NioByteString path for direct buffers.

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-15592

How was this patch tested?

Benchmark run on m3 mac/ARM with 14 cores producing the following results:

--- scaling summary writeSize=4096KB ---

threads	direct MB/s	heap MB/s	heap/direct	direct eff.	heap eff.

   1 |      5,098.0 |      5,624.6 |       1.10x |       1.00 |       1.00
   2 |      9,326.6 |     10,766.9 |       1.15x |       0.91 |       0.96
   4 |     17,293.4 |     18,886.2 |       1.09x |       0.85 |       0.84
   7 |     24,220.6 |     27,652.1 |       1.14x |       0.68 |       0.70
  14 |     25,092.3 |     31,294.6 |       1.25x |       0.35 |       0.40
  28 |     26,017.8 |     28,899.0 |       1.11x |       0.18 |       0.18
  42 |     27,288.1 |     30,836.3 |       1.13x |       0.13 |       0.13

--- scaling summary writeSize=3072KB ---

threads	direct MB/s	heap MB/s	heap/direct	direct eff.	heap eff.

   1 |      6,441.7 |      7,407.9 |       1.15x |       1.00 |       1.00
   2 |     12,718.8 |     14,405.9 |       1.13x |       0.99 |       0.97
   4 |     24,420.3 |     27,779.9 |       1.14x |       0.95 |       0.94
   7 |     39,524.5 |     44,928.1 |       1.14x |       0.88 |       0.87
  14 |     47,319.0 |     58,903.6 |       1.24x |       0.52 |       0.57
  28 |     41,418.1 |     50,173.2 |       1.21x |       0.23 |       0.24
  42 |     39,672.7 |     50,588.1 |       1.28x |       0.15 |       0.16

--- scaling summary writeSize=2048KB ---

threads	direct MB/s	heap MB/s	heap/direct	direct eff.	heap eff.

   1 |      5,092.0 |      5,753.0 |       1.13x |       1.00 |       1.00
   2 |      9,601.4 |     10,889.3 |       1.13x |       0.94 |       0.95
   4 |     17,719.7 |     18,854.6 |       1.06x |       0.87 |       0.82
   7 |     24,087.2 |     27,649.2 |       1.15x |       0.68 |       0.69
  14 |     26,875.0 |     30,787.4 |       1.15x |       0.38 |       0.38
  28 |     26,819.5 |     30,021.1 |       1.12x |       0.19 |       0.19
  42 |     27,593.0 |     30,644.9 |       1.11x |       0.13 |       0.13

--- scaling summary writeSize=1024KB ---

threads	direct MB/s	heap MB/s	heap/direct	direct eff.	heap eff.

   1 |      5,059.7 |      5,682.8 |       1.12x |       1.00 |       1.00
   2 |      9,736.1 |     10,943.2 |       1.12x |       0.96 |       0.96
   4 |     17,766.6 |     19,292.5 |       1.09x |       0.88 |       0.85
   7 |     24,588.8 |     28,444.3 |       1.16x |       0.69 |       0.72
  14 |     27,671.9 |     31,524.6 |       1.14x |       0.39 |       0.40
  28 |     26,259.2 |     30,340.7 |       1.16x |       0.19 |       0.19
  42 |     27,058.7 |     30,937.3 |       1.14x |       0.13 |       0.13

--- scaling summary writeSize=512KB ---

threads	direct MB/s	heap MB/s	heap/direct	direct eff.	heap eff.

   1 |      4,843.5 |      5,502.6 |       1.14x |       1.00 |       1.00
   2 |      9,165.2 |     10,428.1 |       1.14x |       0.95 |       0.95
   4 |     17,641.7 |     19,249.4 |       1.09x |       0.91 |       0.87
   7 |     24,383.0 |     27,974.6 |       1.15x |       0.72 |       0.73
  14 |     27,056.3 |     30,301.9 |       1.12x |       0.40 |       0.39
  28 |     27,436.6 |     30,545.3 |       1.11x |       0.20 |       0.20
  42 |     27,118.8 |     30,685.3 |       1.13x |       0.13 |       0.13 

--- scaling summary writeSize=256KB ---

threads	direct MB/s	heap MB/s	heap/direct	direct eff.	heap eff.

   1 |      4,985.1 |      5,655.3 |       1.13x |       1.00 |       1.00
   2 |      9,738.0 |     10,646.6 |       1.09x |       0.98 |       0.94
   4 |     17,132.0 |     19,142.1 |       1.12x |       0.86 |       0.85
   7 |     24,196.4 |     28,211.3 |       1.17x |       0.69 |       0.71
  14 |     27,048.4 |     31,631.4 |       1.17x |       0.39 |       0.40
  28 |     27,276.7 |     28,319.7 |       1.04x |       0.20 |       0.18
  42 |     26,891.1 |     30,444.4 |       1.13x |       0.13 |       0.13