RFR: 8313452: Improve Classfile API attributes handling safety [v3]

[Adam Sotona]

> This PR improved Classfile API attributes handling safety by introduction of attribute stability indicator
> and by extension of UnknownAttributesOption to more general AttributesProcessingOption.

Adam Sotona has updated the pull request incrementally with one additional commit since the last revision:

  magic moved to Util::isAttributeAllowed and fixed possible NPE

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Changes:
  - all: https://git.openjdk.org/jdk/pull/15101/files
  - new: https://git.openjdk.org/jdk/pull/15101/files/ce77e2ae..392ba560

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15101&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15101&range=01-02

  Stats: 20 lines in 2 files changed: 12 ins; 7 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/15101.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15101/head:pull/15101

PR: https://git.openjdk.org/jdk/pull/15101