RFR: 8336754: Remodel TypeAnnotation to "has" instead of "be" an Annotation [v6]

[Chen Liang]

> `TypeAnnotation` is not an annotation, as it should not be used in places like `AnnotationValue.ofAnnotation`. Thus it's remodeled to contain an annotation at a given location instead of to be an annotation.
> 
> Depends on #20205.

Chen Liang has updated the pull request incrementally with three additional commits since the last revision:

 - More refinements from alex
 - Artifact -> construct
 - More about Annotation, add equals note

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Changes:
  - all: https://git.openjdk.org/jdk/pull/20247/files
  - new: https://git.openjdk.org/jdk/pull/20247/files/beb92159..cf16e7ee

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=20247&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=20247&range=04-05

  Stats: 73 lines in 4 files changed: 52 ins; 0 del; 21 mod
  Patch: https://git.openjdk.org/jdk/pull/20247.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/20247/head:pull/20247

PR: https://git.openjdk.org/jdk/pull/20247