RFR: 8309881: Qualified name of a type element depends on its origin (source vs class) [v2]

[Adam Sotona]

> `javax.lang.model.type.TypeMirror::toString` says: "Any names embedded in the result are qualified if possible."
> However in reality the form of the names depends on the source vs.class origin.
> 
> This patch enforces qualified name to be used.
> 
> Please review.
> 
> Thanks,
> Adam

Adam Sotona has updated the pull request incrementally with one additional commit since the last revision:

  Suggested test revealed the fix is not sufficient
  
  Co-authored-by: jlahoda

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Changes:
  - all: https://git.openjdk.org/jdk/pull/18917/files
  - new: https://git.openjdk.org/jdk/pull/18917/files/1023edfe..16b72b98

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18917&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18917&range=00-01

  Stats: 76 lines in 2 files changed: 75 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/18917.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18917/head:pull/18917

PR: https://git.openjdk.org/jdk/pull/18917