RFR: 8271419: Refactor test code for modifying CDS archive contents [v3]

[Yumin Qi]

> The code for modifying CDS archive content could be used by other tests so the common code is refactored into a util class CDSArchiveUtils.
> 
> Tests: tier1,tier4
> 
> Thanks
> Yumin

Yumin Qi has updated the pull request incrementally with one additional commit since the last revision:

  Fix the FileChannel issue, remove added checkes and no-need imports

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/4945/files
  - new: https://git.openjdk.java.net/jdk/pull/4945/files/10104904..9dc84ec6

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=4945&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=4945&range=01-02

  Stats: 41 lines in 2 files changed: 16 ins; 15 del; 10 mod
  Patch: https://git.openjdk.java.net/jdk/pull/4945.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/4945/head:pull/4945

PR: https://git.openjdk.java.net/jdk/pull/4945