RFR: 6832: Should allow plotting line charts for all quantities [v4]

[Aymane Harmaz]

> This PR makes sure line charts cover all the events across multiple IItemIterables, and makes it possible for linear quantities to be represented as line charts on custom pages.

Aymane Harmaz has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains four commits:

 - prevented access when no more elements are available
 - update copyright year in AttributeComponentConfiguration
 - implemented merge sorting of items from multiple chunks
 - 6832: Should allow plotting line charts for all quantities

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Changes: https://git.openjdk.org/jmc/pull/688/files
  Webrev: https://webrevs.openjdk.org/?repo=jmc&pr=688&range=03
  Stats: 170 lines in 5 files changed: 135 ins; 12 del; 23 mod
  Patch: https://git.openjdk.org/jmc/pull/688.diff
  Fetch: git fetch https://git.openjdk.org/jmc.git pull/688/head:pull/688

PR: https://git.openjdk.org/jmc/pull/688