RFR: 8298277: Replace "session" with "scope" for FFM access [v2]

[Per Minborg]

> This PR suggests renaming various names from "session" to "scope" in accordance with https://openjdk.org/jeps/434
> 
> The PRs contains changes for several sub-components.

Per Minborg has updated the pull request incrementally with one additional commit since the last revision:

  Revert renaming of MemorySessionImpl

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/11573/files
  - new: https://git.openjdk.org/jdk/pull/11573/files/71a5e29c..39f09aa0

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11573&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11573&range=00-01

  Stats: 172 lines in 25 files changed: 0 ins; 0 del; 172 mod
  Patch: https://git.openjdk.org/jdk/pull/11573.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11573/head:pull/11573

PR: https://git.openjdk.org/jdk/pull/11573