API Rescue Master Branch PR: Remove deprecated CMSPageHistoryViewer

[GuySartorelli]

Rescues https://github.com/silverstripe/silverstripe-cms/commit/cb737aa842a3b980c709e564d98846c1cf4310e6

Parent issue

• https://github.com/silverstripe/silverstripe-framework/issues/10350

[GuySartorelli]

Code in silverstripe/versioned-admin (which is where HistoryControllerFactory lives) cannot be removed in this PR. I will create a new PR to remove that, but it should not hold up this PR from being merged.

edit: The new PR: https://github.com/silverstripe/silverstripe-versioned-admin/pull/251

[GuySartorelli]

I have added a new commit to remove the css for the history controller.

[GuySartorelli]

Needs https://github.com/silverstripe/silverstripe-asset-admin/pull/1290 and https://github.com/silverstripe/silverstripe-postgresql/pull/135 to be merged for CI to go green.

[emteknetnz]

Both other PRs have been merged, rerunning tests

[GuySartorelli]

The current CI failure will be resolved when https://github.com/silverstripe/silverstripe-framework/pull/10479 is merged (though there will likely be others after that)