RFR: 8281305: Test com/sun/net/httpserver/simpleserver/MapToPathTest.java fails on Windows 11

[Julia Boes]

This change adds a check for URI path segments that look like a root drive on Windows, e.g. "C:". Such path segments are not supported because a request path should really be relative to the working directory.

The check is implemented with a platform-specific helper class, some additional test cases are included.

Testing: tier 1-3, common Windows versions.

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Commit messages:
 - initial commit

Changes: https://git.openjdk.java.net/jdk/pull/7478/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7478&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8281305
  Stats: 138 lines in 4 files changed: 131 ins; 0 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7478.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7478/head:pull/7478

PR: https://git.openjdk.java.net/jdk/pull/7478