Allow ogr_layer_algebra -input_lyr ALL

[jidanni]

Feature description

In #10270

Input datasource has more than just a single layer, so you should specify which layer with -input_lyr

OK, but there should also be a way to say "use all layers".

Else e.g., we have a map of the 50 states, but are restricted to only being able to use a single state.

[rouault]

nah, too complicated. Compose utilities and use ogrmerge before