RFR: 8313367: SunMSCAPI cannot read Local Computer certs w/o Windows elevation [v3]

[rebarbora-mckvak]

> This fixes the defect described at https://bugs.openjdk.org/browse/JDK-8313367
> 
> If the process does not have write permissions, the store is opened as read-only (instead of failing).
> 
> Please note that permissions to use a certificate in a local machine store must be granted - in a management console, select a certificate, right-click -> All tasks... -> Manage Private Keys... -> add Full control to user.

rebarbora-mckvak has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains two commits:

 - 8313367: signHash finds a key in the local machine store
 - 8313367: Local Computer store is opened with max. allowed permissions

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Changes: https://git.openjdk.org/jdk/pull/16687/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=16687&range=02
  Stats: 12 lines in 1 file changed: 9 ins; 2 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/16687.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16687/head:pull/16687

PR: https://git.openjdk.org/jdk/pull/16687