RFR: 8343074: test/jdk/com/sun/net/httpserver/docs/test1/largefile.txt could be generated [v4]

[Volkan Yazici]

> Adds `test.lib.Utils::createTempFileOfSize` to generate `test/jdk/com/sun/net/httpserver/docs` contents at runtime. This directory contains `largefile.txt` of size 2.6MiB showing up as the 4th largest file tracked by git:
> 
> 
> $ git ls-files | while read f; do echo -e $(stat -c %s "$f")"\t$f"; done >/tmp/trackedFileSizes.txt
> $ sort -n /tmp/trackedFileSizes.txt | tail -n 4
> 2730088	test/jdk/com/sun/net/httpserver/docs/test1/largefile.txt
> 2798680	src/java.base/share/data/unicodedata/NormalizationTest.txt
> 3574947	test/jdk/java/foreign/libTestDowncallStack.c
> 7128495	test/jdk/java/foreign/libTestUpcallStack.c
> 
> 
> **Other highlights:**
> 
> - `jdk.httpclient.test.lib.common.TestUtil` is removed in favor of similar alternatives in `test.lib.Utils` and `test.lib.Asserts`
> - `test.lib.Asserts::assertFileContentsEqual` is added

Volkan Yazici has updated the pull request incrementally with two additional commits since the last revision:

 - Assert that multiple files can be served using the same `FileServerHandler`
 - Remove redundant `@build` dependencies

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/23401/files
  - new: https://git.openjdk.org/jdk/pull/23401/files/a7c44540..4efc42f7

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=23401&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=23401&range=02-03

  Stats: 23 lines in 7 files changed: 10 ins; 7 del; 6 mod
  Patch: https://git.openjdk.org/jdk/pull/23401.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/23401/head:pull/23401

PR: https://git.openjdk.org/jdk/pull/23401