Prior revision deletion form can easily cause out-of-memory errors

Problem/Motivation

The module adds a checkbox and table to the revision deletion form that allows you to delete prior revisions. The table is unbounded and attempts to load all revisions of the node to do this. If this is possible and you check the box to delete the prior revisions a batch is created with an operation per revision. Neither of these approaches is correct.

Steps to reproduce

Create a node with thousands of revisions and visit the revision delete form of one of the newest revisions.

Proposed resolution

• Limit the table to the next 20 revisions and then provide a count.
• Create the batch with revision ID to delete prior revisions to and rerun the same batch till there are no more revisions to delete.

Remaining tasks

User interface changes

• The revision delete page no longer has a table with every prior revision in it. The table is limited to 20 revisions - it provides a count and adds a row saying how many more if there are more than 20 prior revisions.
• The batch messages have been tweaked to account for skipping revisions due to default revision or active revision for a langcode.

API changes

• NodeRevisionDeleteBatch / NodeRevisionDeleteBatchInterface tweaked to support only one batch operation instead of an operation per revision. Note NodeRevisionDeleteBatch should not be considered API.
• NodeRevisionDelete::getPreviousRevisions() deprecated in favour of getPreviousRevisionIds()

Data model changes

None