[foreign-memaccess+abi] RFR: 8296417: Make memory session a pure lifetime abstraction

[Maurizio Cimadamore]

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Commit messages:
 - Fix stale references to MemorySession
 - Add missing copyrights
 - Initial push

Changes: https://git.openjdk.org/panama-foreign/pull/750/files
 Webrev: https://webrevs.openjdk.org/?repo=panama-foreign&pr=750&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8296417
  Stats: 2374 lines in 107 files changed: 667 ins; 846 del; 861 mod
  Patch: https://git.openjdk.org/panama-foreign/pull/750.diff
  Fetch: git fetch https://git.openjdk.org/panama-foreign pull/750/head:pull/750

PR: https://git.openjdk.org/panama-foreign/pull/750