RFR: JDK-8325874: Improve checkbox-based interface in summary pages [v2]

[Hannes Wallnöfer]

> Please review a change to improve the user experience and implementation for the checkbox-based interface to selectively display content on API summary pages:
> 
>  - Add a checkbox to toggle (select/unselect) all checkboxes in the page.
>  - Remove the `Table.setAlwaysShowDefaultTab(boolean)` setter as it is redundant and can be replaced by `!renderTabs`.
>  - Consolidate the code to generate checkboxes into a new protected `SummaryListWriter.getCheckbox` method.

Hannes Wallnöfer has updated the pull request incrementally with one additional commit since the last revision:

  Review feedback

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Changes:
  - all: https://git.openjdk.org/jdk/pull/18194/files
  - new: https://git.openjdk.org/jdk/pull/18194/files/cb37764d..d7460e8d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=18194&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=18194&range=00-01

  Stats: 2 lines in 2 files changed: 0 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/18194.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/18194/head:pull/18194

PR: https://git.openjdk.org/jdk/pull/18194