RFR: 8366475: Rename MetaspaceShared class to AOTMetaspace [v4]

[Ioi Lam]

> This PR is one (of many) steps in [JDK-8366473](https://bugs.openjdk.org/browse/JDK-8366473) (Refactor CDS source code with new AOT terminology):
> 
> Rename this class to with a naming convention that's consistent with other new AOT classes such as AOTClassLinker.
> 
> All changes are mechanical text replacement. Headers are resorted alphabetically.

Ioi Lam has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 11 commits:

 - Fixed include order
 - Merge branch 'master' into 8366475-rename-metaspace-shared-to-aot-metaspace
 - Merge branch '8366474-rename_metaspaceobj_is_shared_to_in_aot_cache' into 8366475-rename-metaspace-shared-to-aot-metaspace
 - Also renamed ConstantPool::is_shared() because it shadows MetaspaceObj::is_shared()
 - Merge branch 'master' into 8366474-rename_metaspaceobj_is_shared_to_in_aot_cache
 - removed unnecessary includes
 - Redo changes in comments and tests
 - Merge branch '8366474-rename_metaspaceobj_is_shared_to_in_aot_cache' into 8366475-rename-metaspace-shared-to-aot-metaspace
 - Removed MetaspaceShared -> AOTMetaspace changes that are intended for https://github.com/openjdk/jdk/pull/27017
 - Rename MetaspaceShared -> AOTMetaspace
 - ... and 1 more: https://git.openjdk.org/jdk/compare/90a2db1e...63073feb

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Changes: https://git.openjdk.org/jdk/pull/27017/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=27017&range=03
  Stats: 367 lines in 60 files changed: 35 ins; 35 del; 297 mod
  Patch: https://git.openjdk.org/jdk/pull/27017.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/27017/head:pull/27017

PR: https://git.openjdk.org/jdk/pull/27017