RFR: 8313452: Improve Classfile API attributes handling safety [v2]

[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 with a new target base due to a merge or a rebase. The pull request now contains 23 commits:

 - fixed javadoc wording
 - HAZMAT renamed to UNSTABLE
   no filtering on read
   filtering on write only for bound attributes
 - Merge branch 'master' into JDK-8313452-attributes-safety
   
   # Conflicts:
   #	src/java.base/share/classes/jdk/internal/classfile/Classfile.java
 - Merge branch 'JDK-8312491-snippets' into JDK-8313452-attributes-safety
 - added notes to attributes
 - fixing javadoc
 - fixing javadoc
 - fixing javadoc
 - fixing javadoc
 - removed extra lines
 - ... and 13 more: https://git.openjdk.org/jdk/compare/744b3970...ce77e2ae

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Changes: https://git.openjdk.org/jdk/pull/15101/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15101&range=01
  Stats: 479 lines in 10 files changed: 374 ins; 29 del; 76 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