RFR: 8344190: Cleanup code in sun.net.www.protocol.http and sun.net.www.protocol.https after JEP 486 integration [v2]

[Jaikiran Pai]

> Can I please get a review of this code which cleans up usages of SecurityManager and related APIs? This addresses https://bugs.openjdk.org/browse/JDK-8344190.
> 
> No new tests have been added and testing of tier1, tier2, tier3 is in progress.

Jaikiran Pai has updated the pull request incrementally with two additional commits since the last revision:

 - mark the authentication classes final
 - clean up windows variant of NTLMAuthentication

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/22232/files
  - new: https://git.openjdk.org/jdk/pull/22232/files/4754e1b9..16193446

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=22232&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=22232&range=00-01

  Stats: 47 lines in 5 files changed: 0 ins; 37 del; 10 mod
  Patch: https://git.openjdk.org/jdk/pull/22232.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/22232/head:pull/22232

PR: https://git.openjdk.org/jdk/pull/22232