RFR: 8339154: Cleanups and JUnit conversion of test/jdk/java/util/zip/Available.java [v3]

[Eirik Bjørsnøs]

> Please review this test-only PR which addresses several issues with the `test/jdk/java/util/zip/Available.java` test:
> 
> * The test is converted to JUnit 5
> * The test now creates its own test vector programmatically instead of relying on a binary `input.jar` test vector 
> * Coverage is added for calling `available()` after calling `ZipInputStream.closeEntry`, as expected by the API specification for `ZipInputStream.available`
> * Coverage is added for calling `available()` on a closed `ZipInputStream`
> * Coverage is added for the unspecified, but long-standing behavior of `ZipFileInputStream.available()` (The InputStream returned for `STORED` entries)
> 
> Additionally, the test is split into multiple methods, adding javadoc comments for each of them.

Eirik Bjørsnøs has updated the pull request incrementally with one additional commit since the last revision:

  Actually make "stored.txt" use the STORED method

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/20744/files
  - new: https://git.openjdk.org/jdk/pull/20744/files/8ae9e0d4..0867317c

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20744&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20744&range=01-02

  Stats: 1 line in 1 file changed: 1 ins; 0 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/20744.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20744/head:pull/20744

PR: https://git.openjdk.org/jdk/pull/20744