RFR: 8372004: Have SSLLogger implement System.Logger [v3]

[Sean Coffey]

> `SSLLogger` utilizes `System.Logger` if the `javax.net.debug` system property key value is empty. However, since that class doesn't implement `SSLogger`, it misses the advantage of highlighting the exact calling site for each log statement.  Having `SSLLogger `simply implement `System.Logger` fixes this
> 
> I've also taken this opportunity to refractor the `isOn` boolean in `SSLLogger`. Encapsulated that boolean in a new method which callers can now use. I also used `ForceInline` directory on that method. Thanks to @dfuch for suggestions on that front.
> 
> Also updated an existing unit testcase to test for the new functionality

Sean Coffey has updated the pull request incrementally with one additional commit since the last revision:

  Review comments from Daniel

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Changes:
  - all: https://git.openjdk.org/jdk/pull/28376/files
  - new: https://git.openjdk.org/jdk/pull/28376/files/2ddecbc4..5cd23089

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=28376&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=28376&range=01-02

  Stats: 7 lines in 1 file changed: 0 ins; 0 del; 7 mod
  Patch: https://git.openjdk.org/jdk/pull/28376.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/28376/head:pull/28376

PR: https://git.openjdk.org/jdk/pull/28376