RFR: JDK-8311644 Server should not send bad_certificate alert when the client does not send any certificates [v2]

[Anthony Scarpino]

> Hi,
> 
> I need a code review of what is really a text change.  This changes the alert type returned during some TLS CertificateMessage failures to what is recommended in [RFC 8446](https://tools.ietf.org/html/rfc8446).  An additional change was to add the alert description to the thrown exception.  This makes it easier for the user to know the alert type and makes testing easier.  Two of the three changes are tested as the final one is too hard to test.  A few tests needed change as they did string comparing on exception messages.
> 
> Tony

Anthony Scarpino has updated the pull request incrementally with one additional commit since the last revision:

  review comments

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Changes:
  - all: https://git.openjdk.org/jdk/pull/17717/files
  - new: https://git.openjdk.org/jdk/pull/17717/files/e382e9e6..24c9dd85

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=17717&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=17717&range=00-01

  Stats: 19 lines in 4 files changed: 1 ins; 6 del; 12 mod
  Patch: https://git.openjdk.org/jdk/pull/17717.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/17717/head:pull/17717

PR: https://git.openjdk.org/jdk/pull/17717