RFR: JDK-8263043: Add test to verify order of tag output

[Jonathan Gibbons]

Please review a new test to verify that the output of block tags is generated in the expected order.

The code in the standard doclet to generate the output is the same for all use sites (modules, packages, class, members) and so just the richest site is tested.

The test checks that tags appear in the expected order by default, but can be reordered in a couple of different ways.

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Commit messages:
 - fix whitespace
 - JDK-8263043: Add test to verify order of tag output

Changes: https://git.openjdk.java.net/jdk/pull/2835/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=2835&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8263043
  Stats: 171 lines in 1 file changed: 171 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/2835.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/2835/head:pull/2835

PR: https://git.openjdk.java.net/jdk/pull/2835