RFR: 8331975: Enable case-insensitive check in ccache and keytab entry lookup

[Weijun Wang]

Add a new system property to control the name comparison in keytab and ccache entry lookup.

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Commit messages:
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Changes: https://git.openjdk.org/jdk/pull/19216/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19216&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8331975
  Stats: 142 lines in 4 files changed: 123 ins; 5 del; 14 mod
  Patch: https://git.openjdk.org/jdk/pull/19216.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19216/head:pull/19216

PR: https://git.openjdk.org/jdk/pull/19216