RFR: 8348986: Improve coverage of enhanced exception messages

[Michael McMahon]

Hi,

Enhanced exception messages are designed to hide sensitive information such as hostnames, IP 
addresses from exception message strings, unless the enhanced mode for the specific category 
has been explicitly enabled. Enhanced exceptions were first introduced in 8204233 in JDK 11 and 
updated in 8207846.

This PR aims to increase the coverage of enhanced exception messages in the networking code.
A limited number of exceptions are already hidden (restricted) by default. The new categories and 
exceptions in this PR will be restricted on an opt-in basis, ie. the default mode will be enhanced
(while preserving the existing behavior).

The mechanism is controlled by the security/system property "jdk.includeInExceptions" which takes as value
a comma separated list of category names, which identify groups of exceptions where the exception
message may be enhanced. Any category not listed is "restricted" which means that potentially
sensitive information (such as hostnames, IP addresses, user identities) are excluded from the message text.

The changes to the java.security conf file describe the exact changes in terms of the categories now
supported and any changes in behavior.

Thanks,
Michael

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Commit messages:
 - remove file added by mistake
 - whitespace
 - moved test
 - Merge branch 'master' into 8348986-exceptions
 - update
 - update
 - Merge branch 'master' into 8348986-exceptions
 - update
 - Merge branch 'master' into 8348986-exceptions
 - Merge branch 'master' into 8348986-exceptions
 - ... and 3 more: https://git.openjdk.org/jdk/compare/b1a21b56...c4419860

Changes: https://git.openjdk.org/jdk/pull/23929/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=23929&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8348986
  Stats: 1002 lines in 42 files changed: 762 ins; 104 del; 136 mod
  Patch: https://git.openjdk.org/jdk/pull/23929.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23929/head:pull/23929

PR: https://git.openjdk.org/jdk/pull/23929