[jdk21u-dev] RFR: 8348986: Improve coverage of enhanced exception messages

[Alexey Bakhtin]

I'd like to backport JDK-8348986 to control sensitive information in Exception messages.

Backport is not clean. The following changes were applied manually:
- src/java.base/share/classes/module-info.java
  - exports jdk.internal.util updated manually because JDK25 has more dependencies 
- src/java.base/share/classes/sun/nio/ch/DatagramSocketAdaptor.java
  - copyright year
- src/java.base/share/classes/sun/nio/ch/SocketAdaptor.java
  - changes discarded. JDK21 does not have JDK-8343791 and related changes (Socket::connect() does not throw UnknownHostException)
- src/java.base/unix/classes/sun/nio/ch/UnixAsynchronousSocketChannelImpl.java
  - trivial merge in the import section, copyright year is updated
- src/java.base/unix/classes/sun/nio/fs/UnixUserPrincipals.java
  - trivial merge in the lookupName() method. JDK21 version still has SecurityManager related code
  - copyright year
- src/java.base/share/classes/sun/net/util/IPAddressUtil.java
  - JDK21 does not have JDK-8272215 It can not be backported because of API changes. validateNumericFormatV4() method is changed instead of invalidIpAddressLiteral
  - copyright year
- src/jdk.httpserver/share/classes/sun/net/httpserver/simpleserver/JWebServer.java
  - setEnhancedExceptions method was added manually because of a context difference
- src/java.base/share/classes/java/net/HostPortrange.java
  - copyright year
- src/java.base/share/classes/java/net/Inet6Address.java
  - changes discarded. JDK21 does not have JDK-8272215 and related functionality. 
- src/java.base/share/classes/java/net/InetAddress.java
  - UnknownHostException in the getLocalHost method is updated manually because of a context difference
  - copyright year
- src/java.base/share/classes/java/net/Proxy.java
  - copyright year
  - import section
- src/java.base/share/classes/java/net/SocketPermission.java
  - copyright year
- src/java.base/share/classes/java/net/SocksSocketImpl.java
  - copyright year
  - import section
- src/java.base/share/classes/java/net/URL.java
  - copyright year
  - import section
- src/java.net.http/share/classes/jdk/internal/net/http/websocket/OpeningHandshake.java
  - copyright year
- src/java.base/share/native/libnet/net_util.c
  - copyright year
- src/java.base/share/native/libnet/net_util.h
  - copyright year
- src/java.base/unix/native/libnet/net_util_md.c
  - copyright year
- src/java.base/windows/classes/sun/nio/ch/WindowsAsynchronousSocketChannelImpl.java
  - copyright year
  - import section
- src/java.base/windows/classes/sun/nio/fs/WindowsUserPrincipals.java
  - copyright year
- src/java.base/share/classes/sun/net/www/protocol/jar/JarFileFactory.java
  - changes discarded. JDK21 does not have JDK-8341142 and related functionality. 

Modified and related JTREG tests are passed

-------------

Commit messages:
 - Backport b6f827ef054959662190e21ce63fc3d3c45b92f3

Changes: https://git.openjdk.org/jdk21u-dev/pull/2132/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk21u-dev&pr=2132&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8348986
  Stats: 977 lines in 44 files changed: 702 ins; 109 del; 166 mod
  Patch: https://git.openjdk.org/jdk21u-dev/pull/2132.diff
  Fetch: git fetch https://git.openjdk.org/jdk21u-dev.git pull/2132/head:pull/2132

PR: https://git.openjdk.org/jdk21u-dev/pull/2132