RFR: 8287379: Using @inheritDoc in an inapplicable context crashes javadoc

[Pavel Rappo]

This rights the wrongs of JDK-8008768. For more information, see the respective CSR.

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Commit messages:
 - Update DocTest
 - Add tests
 - Disallow @inheritDoc in type declarations
 - Do not warn on inline misuse
 - Doclint shouldn't warn on inapplicable conditions
 - Expand checkTags to include non-inline tag
 - Remove another null-check
 - Remove null-check

Changes: https://git.openjdk.org/jdk19/pull/54/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk19&pr=54&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8287379
  Stats: 499 lines in 17 files changed: 193 ins; 234 del; 72 mod
  Patch: https://git.openjdk.org/jdk19/pull/54.diff
  Fetch: git fetch https://git.openjdk.org/jdk19 pull/54/head:pull/54

PR: https://git.openjdk.org/jdk19/pull/54