3rd-party should be able to alter the EntityListBuilder rows

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this was previously tagged for a change record which still needs to happen
MR should be updated for 10.1 and there was 1 open thread that should be addressed.

Thanks.

What if I would like to add a new column?
Then I should be able to add field into the ::buildHeader() as well. Not just in the ::buildRow()

What if I would like to add something above or below the table?
What if I would like to add new rows to the table? For example with colspan=42 which contains a long description which belong to the previous or next row.

Then it would be useful to have a dispatched event in the ::render(), to be able to alter the whole $build render array.

This issue can be a quick fix for the problem.

Most of the time EntityListBuilder is used for config entities (in the original topic there is a use case for NodeListBuilder).

What is the user story here?

As a side builder I would like to be able make changes on pre-defined lists, such as "Node types", "Image Styles", "Block types", "User roles" and so on.

• modify existing fields
• remove existing fields
• add new fields
• alter filtering options
• alter sorting options
• change the layout of the listed items (table vs anything else)

For me this sound like a task for "views".
Unfortunately, event the config_views → can't handle this task properly, because there is not enough support and metadata on config schema.

This is also related: #2318187: FieldDefinitionInterfacegetDefaultValue() requires an entity →

I think the whole EntityListBuilder concept should be replaced with a views based solution.