RFR: 8307143: CredentialsCache.cacheName should not be static [v4]

[Weijun Wang]

> The CC can be loaded with any file and its name is not static.
> 
> `MemoryCredentialsCache` is removed since it's not used anywhere. We've already supported native ccache reading directly with JNI method `Credentials::acquireDefaultNativeCreds`.

Weijun Wang has updated the pull request incrementally with one additional commit since the last revision:

  copyright years

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Changes:
  - all: https://git.openjdk.org/jdk/pull/13737/files
  - new: https://git.openjdk.org/jdk/pull/13737/files/f593c1ed..33f9f599

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=13737&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=13737&range=02-03

  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/13737.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13737/head:pull/13737

PR: https://git.openjdk.org/jdk/pull/13737