Provide support for Views Entity Reference Filter (VERF)

I don't think we need that module as a dependency. If this is just a views filter than we can create a custom version of that for our needs. We would just need to create that here: https://git.drupalcode.org/project/custom_field/-/tree/3.1.x/src/Plugin/... and modify the filter type here: https://git.drupalcode.org/project/custom_field/-/blob/3.1.x/custom_fiel...

I can take a look at it when I get more time but open to patches if you wanna take a stab at it first.

@apmsooner you make a good point that we could just add a custom filter. My thinking was that since 9x as many sites are already using VERF as are using Custom Field, and since Custom Field already has 5 submodules including integrations with GraphQL and Linkit, this could just be one more submodule providing an integration.

never mind my objections, @apmsooner, I will use your simpler approach. Thank you for the feedback!

Ready for review!

@benstallings,

Thanks for your work on this! Please just fix the new phpcs and phpstan warnings introduced from this code for now and I'll try to do a full review as soon as I can get to it.

Thanks