RFR: 8332070: Convert package.html files in `java.management` to package-info.java

[Nizar Benalla]

This is a simple noreg cleanup. The motivation was that I noticed javac doesn't recognise package.html files well.

Some of the contents of the `package.html` files (and code in the package) may be outdated, but I think it is out of scope for this PR.

I have also changed three `{@link }` usages with the `href` that would have been in the generated HTML.
Because referencing an element from an other module wouldn't work even when using the `module/package.class#member`, if the `module-info.java` file does not have "require `<name>`".

I am referring to line 69 in 
`src/java.management/share/classes/javax/management/monitor/package-info.java`
and lines 90 and 120 in 
`src/java.management/share/classes/javax/management/remote/package-info.java`

Adding 2 dependencies just for 3 links didn't seem right.

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Commit messages:
 - 8332070: Convert package.html files in `java.management` to package-info.java

Changes: https://git.openjdk.org/jdk/pull/19399/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=19399&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8332070
  Stats: 3091 lines in 18 files changed: 1526 ins; 1565 del; 0 mod
  Patch: https://git.openjdk.org/jdk/pull/19399.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/19399/head:pull/19399

PR: https://git.openjdk.org/jdk/pull/19399