RFR: 8290824: Use InputStream.readAllBytes() instead of surrogate code

[Сергей Цыпанов]

We can use `InputStream.readAllBytes()` in `ModuleHashes` and `X509CertPath`.

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Commit messages:
 - 8290824: Remove unused JavaDoc
 - 8290824: Use InputStream.readAllBytes() instead of surrogate code

Changes: https://git.openjdk.org/jdk/pull/9596/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=9596&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8290824
  Stats: 30 lines in 2 files changed: 0 ins; 21 del; 9 mod
  Patch: https://git.openjdk.org/jdk/pull/9596.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/9596/head:pull/9596

PR: https://git.openjdk.org/jdk/pull/9596