Add self_checkout field to shop=supermarket

[Dimitar5555]

Description, Motivation & Context

A lot of newly built supermarkets have self checkout lanes. Existing ones are also retrofitted with self checkout lanes, which replace part (or all in some cases) of the serviced lanes. It is helpful to know if a shop has self checkout, since it is almost always faster, especially when you need a few things.

Related issues

Supercedes #1353

Links and data

Relevant OSM Wiki links:

• https://wiki.openstreetmap.org/wiki/Key%3Aself_checkout

Relevant tag usage stats:

1200 total instances, of which 675 are used on shop=supermarket

https://taginfo.openstreetmap.org/keys/self_checkout

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[tordans]

I wonder if we should move this to the more fields due to the low usage. Then again that is something that most supermarkets will get at some point.

We could also consider adding it to hardware stores. At least in Germany. (Possibly in a separate PR)

[matkoniecz]

Given that it is something with quite low usefulness as far as data goes and will appear in basically any supermarket (at least in countries with higher labour costs) I support moving to showing it only if tagged already.

[Dimitar5555]

I've moved it to moreFields.

[Dimitar5555]

Test-Documentation (as a moreField)

Preview links & Sidebar Screenshots

Prefilled	Adding the field (can't catch it with the dropdown open)

Search

n/a

Info-i

Wording

• American English
• name, aliases (if present) use Title Case
• [N/A] terms (if present) use lower case, sorted A-Z

[matkoniecz]

closing/reopening to get preview working again

[tyrasd]

I think this PR is slightly better than #1353 as for many shop types, self-checkout is so rare that it does not make sense to include it even as a moreFields field. So, let's start with supermarkets. If needed, we can later add it to more particular shop types.