RFR: 8341775: Duplicate manifest files are removed by jarsigner after signing [v11]

[Kevin Driver]

> JDK-8341775: In the case where there is a *single* META-INF directory but potentially *multiple* manifest files of different cases, print a warning before selecting the first one and ignoring the rest (the current behavior should be maintained).

Kevin Driver has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 15 commits:

 - merge master
 - merge master
 - code review comments
 - code review comments
 - review comments
 - force-add jar
 - re-write to make the changes in the jarsigner tool itself, rather than the API
 - Revert "JDK-8341775: In the case where there is a *single* META-INF directory but potentially *multiple* manifest files of different cases, print a warning before selecting the first one and ignoring the rest."
   
   This reverts commit 06e90503f3e75b1b432ec0a196716f01ebb7344a.
   
   # Please enter the commit message for your changes. Lines starting
   # with '#' will be kept; you may remove them yourself if you want to.
   # An empty message aborts the commit.
   #
   # On branch 8341775
   # Your branch is up to date with 'origin/8341775'.
   #
   # Changes to be committed:
   #	modified:   src/jdk.jartool/share/classes/jdk/security/jarsigner/JarSigner.java
   #
 - Merge remote-tracking branch 'origin/master' into 8341775
   # Please enter a commit message to explain why this merge is necessary,
   # especially if it merges an updated upstream into a topic branch.
   #
   # Lines starting with '#' will be ignored, and an empty message aborts
   # the commit.
 - Merge branch 'master' of github.com:openjdk/jdk into 8341775
   # Please enter a commit message to explain why this merge is necessary,
   # especially if it merges an updated upstream into a topic branch.
   #
   # Lines starting with '#' will be ignored, and an empty message aborts
   # the commit.
 - ... and 5 more: https://git.openjdk.org/jdk/compare/771e160d...e4677965

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Changes: https://git.openjdk.org/jdk/pull/22222/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=22222&range=10
  Stats: 111 lines in 3 files changed: 111 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/22222.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22222/head:pull/22222

PR: https://git.openjdk.org/jdk/pull/22222