RFR: 8323794: Remove unused jimage compressor plugin configuration

[Claes Redestad]

There's an unused concept of a pluginConfig that is passed into the jlink compress plugins, however we always pass null here and the code seems broken (the pluginConfig wouldn't have been stored properly). This seem to be a left-over from a more generic plugin design that never came to fruition.

This PR cleans out this code from the plugins and decompressors, while keeping the compressed header format intact for backwards compatibility (and in case we want to revisit this in the future)

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Commit messages:
 - 8323794: Remove unused jimage compressor plugin configuration

Changes: https://git.openjdk.org/jdk/pull/17443/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=17443&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8323794
  Stats: 67 lines in 12 files changed: 2 ins; 39 del; 26 mod
  Patch: https://git.openjdk.org/jdk/pull/17443.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17443/head:pull/17443

PR: https://git.openjdk.org/jdk/pull/17443